Neural Activity in Macaque Parietal Cortex Reflects Temporal Integration of Visual Motion Signals during Perceptual Decision Making

Probably not a substantial claim: may not pass S3 (load-bearing).

Variations in task geometry, such as differences between dot motion direction and saccade target locations, had negligible effects on reaction time and accuracy.

“Variations in task geometry (e.g., differences between dot motion direction and saccade target locations) had negligible effects on RT and accuracy.”

May combine two claims.

LIP neurons typically discharged more on trials with positive-direction pulses than on trials with no pulse, and less on negative-direction pulse trials than on no-pulse trials (positive direction, +1.00 ± 0.21 spikes/s; negative-direction, −0.89 ± 0.22 spikes/s; mean ± SE).

“LIP neurons typically discharged more on trials with positive-direction pulses than on trials with no pulse, and less on negative-direction pulse trials than on no-pulse trials (positive direction, ϩ1.00 Ϯ 0.21 spikes/s; negative-direction, Ϫ0.89 Ϯ 0.22 spikes/s; mean Ϯ SE) (Fig. 7 A, B).”

May combine two claims.

Neural activity in area LIP depended on the strength and direction of random dot motion and was further perturbed by the motion pulses.

“Neural activity in area LIP depended on the strength and direction of random dot motion, as shown previously (Shadlen and Newsome, 2001;Roitman and Shadlen, 2002), and was further perturbed by the motion pulses.”

• cites Shadlen and Newsome, 2001Not checked yet

  Not checked in the free run.

• cites Roitman and Shadlen, 2002Not checked yet

  Not checked in the free run.

May combine two claims.

The pulses caused an increase or decrease in simulated spike rate of 1.5-2.5 spikes/s, and this difference diminished gradually over the ensuing ~625 ms.

“As shown in Figure 9C, the pulses caused an increase or decrease in simulated spike rate of 1.5-2.5 spikes/s.This difference diminished gradually over the ensuing ϳ625 ms.”

• AssumptionThe authors state this as an assumption: LIP neurons represent the perfect time integral of the difference in firing rates between opposing direction-selective pools of neurons in area MT.
• AssumptionThe authors state this as an assumption: The decision process terminates when the pooled activity from one of the LIP populations reaches a criterion level of firing rate.

May combine two claims.

The pulse effects in the data were somewhat smaller than predicted and not quite as persistent.

“However, the pulse effects in our data were somewhat smaller than predicted and not quite as persistent.”

May combine two claims.

The background pulses did not affect choice and RT by different amounts (δ = −0.05% motion coherence; no significant improvement in fit by likelihood ratio test, p = 0.70).

“We allowed for the possibility that the background pulses might affect choice and RT by different amounts, but we failed to find evidence to support this (Eq.7; ␦ ϭ Ϫ0.05% motion coherence; no significant improvement in fit by likelihood ratio test, p ϭ 0.70).”

• AssumptionThe authors state this as an assumption: For all motion strengths and pulse conditions, the height of the decision bounds, the constant of proportionality from motion strength to momentary evidence, and the mean nondecision time are common.

May combine two claims.

The direction-, coherence-, and time-dependent responses illustrated by the sample neuron are representative of the sample of 54 LIP neurons and are consistent with previous findings from the authors' laboratory (Roitman and Shadlen, 2002).

“The direction-, coherence-, and time-dependent responses illustrated by this neuron are representative of the sample of 54 LIP neurons and are consistent with previous findings from our laboratory (Roitman and Shadlen, 2002).”

• cites Roitman and Shadlen, 2002Not checked yet

  Not checked in the free run.

May combine two claims.

Motion pulses exerted systematic effects on both choices and RTs.

“Nonetheless, motion pulses exerted systematic effects on both choices and RTs.”

May combine two claims.

The model provides a coherent explanation of the monkeys' behavior and the LIP responses on trials without a pulse.

“The model provides a coherent explanation of the monkeys' behavior and the LIP responses on trials without a pulse, on the assumption that LIP neurons represent the integral of the difference in firing rates between direction-selective neurons in MT.”

• AssumptionThe authors state this as an assumption: LIP neurons represent the perfect time integral of the difference in firing rates between opposing direction-selective pools of neurons in area MT.

May combine two claims.

Strong motion in either direction led to near-perfect direction discrimination: almost all preferred-target choices for strong positive motions and almost no preferred-target choices for strong negative motions.

“Strong motion in either direction led to nearperfect direction discrimination: almost all preferred-target choices for strong positive motions and almost no preferredtarget choices for strong negative motions (i.e., all null-target choices).”

May combine two claims.

At the strongest positive and negative motion strengths, the monkeys made their decisions relatively quickly, whereas at lower motion strengths, they took progressively longer.

“At the strongest positive and negative motion strengths, the monkeys made their decisions relatively quickly, whereas at lower motion strengths, the monkeys took progressively longer to complete trials.”

Classified as probably not a substantial claim. May combine two claims.

Pulse effects measured in the study were subtle, and many analyses benefit from combining all data across recording sessions and across monkeys.

“The pulse effects we measured were subtle, and many of our analyses benefit from the power achieved by combining all our data across recording sessions and across monkeys.”

May combine two claims.

Similar effects of motion pulses on choices and RTs were observed in both monkeys, although the absolute magnitude of the pulse effect was stronger for one monkey than the other.

“Similar effects of the motion pulses on choices and RTs were observed in both of the monkeys, although the absolute magnitude of the pulse effect was stronger for one monkey than the other (Table 2).”

May combine two claims.

Pulses affected choices that occurred ~300 ms after pulse onset; trials with saccadic responses initiated earlier relative to the pulse showed no significant effect of the pulse.

“As shown in Figure 4, pulses affected the choices that occurred ϳ300 ms after pulse onset; trials in which saccadic responses were initiated earlier relative to the pulse showed no significant effect of the pulse.”

May combine two claims.

The slopes of the ramping LIP responses depended on the strength of the motion signal: stronger motions in the preferred direction corresponded to faster rates of increase, and stronger motions in the null direction corresponded to faster rates of decrease.

“The slopes of these ramping responses depended on the strength of the motion signal: stronger (or weaker) motions in the preferred direction corresponded to faster (or slower) rates of increase, and stronger (or weaker) motions in the null direction corresponded to faster (or slower) rates of decrease.”

May combine two claims.

LIP responses depended on the dot direction, motion coherence, and amount of viewing time.

“These responses also depended on the dot direction, motion coherence, and amount of viewing time.”

May combine two claims.

A positive-direction pulse increased the probability of a preferred-target choice, and a negative-direction pulse decreased the probability of a preferred-target choice.

“The insertion of a positivedirection pulse increased the probability of the monkey making a preferred-target choice, and the presentation of a negativedirection pulse decreased the probability of a preferred-target choice (Fig. 3A, green and red points).”

May combine two claims.

The 100-ms-long pulses affected LIP spike rates for ~575 ms, indicating that LIP activity reflects sensory events that occurred over the previous half-second or more.

“Thus, the 100-ms-long pulses affected LIP spike rates for ϳ575 ms, indicating that LIP activity reflects sensory events that occurred over the previous half-second or more.”

May combine two claims.

The effects of motion pulses on LIP activity became evident ~225 ms after pulse onset and persisted until ~800 ms after the pulse.

“The effects of motion pulses became evident ϳ225 ms after the onset of the pulse and persisted until ϳ800 ms after the pulse.”

May combine two claims.

The modulations of response after positive- and negative-direction pulses were significant across the sample of LIP neurons (F(2,159) = 22.28; p < 10^−8, one-way ANOVA) and were individually significant in one-third (18) of the neurons studied.

“These modulations of response after positive-and negative-direction pulses were significant across our sample of LIP neurons (F (2,159) ϭ 22.28; p Ͻ 10 Ϫ8 , one-way ANOVA) and were individually significant in one-third (18) of the neurons studied (positive direction Ͼ negative direction; t test, p Ͻ 0.05; 13 of 35 in monkey I, 5 of 19 in monkey S).”

May combine two claims.

An averaging artifact in the inset graph should delay the effect of pulses, but the time course looks very similar to the overall population average.

“An averaging artifact in this graph should delay the effect of pulses, but the time course looks very similar to the overall population average (Fig. 6, main panel).”

May combine two claims.

Pulse effects in the two monkeys were similar to the averaged data, although both psychophysical and physiological pulse effects were slightly stronger in monkey I than monkey S.

“Likewise, pulse effects in the two monkeys were similar to the averaged data, although both the psychophysical and physiological pulse effects were slightly stronger in monkey I than monkey S (see above) (Table 2).”

May combine two claims.

The pulses affected choices over a similar range of times but lagged the LIP changes by ~75-100 ms.

“The pulses affected choices over a similar range of times but lagged the LIP changes by ϳ75-100 ms (Fig. 4).”

May combine two claims.

Brief perturbations of the stimulus have long-lasting effects on both decisions and neural activity.

“Our findings provide direct support for this time-integral computation by demonstrating that brief perturbations of the stimulus have long-lasting effects on both decisions and neural activity.”

May combine two claims.

The pulses first affected LIP activity ~225 ms after onset and caused detectable changes in firing rate for another ~575 ms.

“The pulses first affected LIP activity ϳ225 ms after onset and caused detectable changes in firing rate for another ϳ575 ms (Fig. 6).”

May combine two claims.

The first 200-225 ms of the LIP response after the onset of the moving dots follows a stereotyped dip-and-rise that reflects neither the strength and direction of motion nor the monkey's choice.

“As shown previously (Roitman and Shadlen, 2002) and as replicated in these experiments, the first 200 -225 ms of the LIP response after the onset of the moving dots follows a stereotyped dip-and-rise that reflects neither the strength and direction of motion nor the monkey's choice.”

• cites Roitman and Shadlen, 2002Not checked yet

  Not checked in the free run.

Classified as probably not a substantial claim.

The latencies in the model ensure that the onset of a pulse (and the onset of motion) begins to affect the LIP firing rates 225 ms after onset.

“The latencies in the model ensure that the onset of a pulse (and the onset of motion) begins to affect the LIP firing rates 225 ms after onset.”

May combine two claims.

The simulated perfect, bounded integrator exhibits a departure from time-shift invariance, but the effect is considerably weaker than in the data (-0.1 spikes/s per 100 ms of pulse onset time; 95% CI, -0.4 to 0.1; p = 0.29).

“Not surprisingly, the simulated perfect, bounded integrator exhibits a departure from time-shift invariance (Fig. 10 B, right).However, the regression demonstrates that the effect is considerably weaker than in the data (Ϫ0.1 spikes/s per 100 ms of pulse onset time; 95% CI, Ϫ0.4 to 0.1; p ϭ 0.29).”

• AssumptionThe authors state this as an assumption: LIP neurons represent the perfect time integral of the difference in firing rates between opposing direction-selective pools of neurons in area MT.
• AssumptionThe authors state this as an assumption: The decision process terminates when the pooled activity from one of the LIP populations reaches a criterion level of firing rate.

May combine two claims.

Although the pulses lasted only 100 ms, their effect on decisions was >0.5 s, lasting from 225 to 800 ms from the time of onset.

“Although the pulses lasted only 100 ms, their effect on decisions was Ͼ0.5 s, lasting from 225 to 800 ms from the time of onset.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Our experiments do not furnish a measurement of the integration time constant.

“Our experiments do not furnish a measurement of the integration time constant.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Mean RTs shown reflect both correct and error trials; a similar pattern is evident for just correct responses.

“Mean RTs shown reflect both correct and error trials; a similar pattern is evident for just correct responses.”

May combine two claims.

Positive-direction pulses sped up RTs for preferred-target choices and slowed down RTs for null-target choices.

“Positive-direction pulses sped up RTs for preferred-target choices and slowed down RTs for null-target choices”

Classified as probably not a substantial claim.

The horizontal displacement of the colored curves equates the pulses with the addition or subtraction of 1.6% coherent motion to the random dots stimulus.

“The horizontal displacement of the colored curves equates the pulses with the addition or subtraction of 1.6% coherent motion to the random dots stimulus.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The time course of the population average pulse effect shown in Fig.6 was not affected by removal of this unit from the population.

“note that the time course of the population average pulse effect shown in Fig.6was not affected by removal of this unit from the population”

May combine two claims.

Background pulses add or subtract less when they occur later during motion viewing; later pulses exerted weaker effects than earlier pulses.

“Background pulses add or subtract less when they occur later during motion viewing.”

• Also stated in: § Discussion · plain

  “Later pulses exerted weaker effects than earlier pulses.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Pulse effects seen in neuron i034 were similar to that observed in the population.

“Pulse effects seen in this neuron (i034) were similar to that observed in the population”

May combine two claims.

The firing rate depends on motion strength during motion viewing and reaches a common level of activity preceding the eye movement response.

“The firing rate depends on motion strength during motion viewing and reaches a common level of activity preceding the eye movement response.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Comparison of a postoperative magnetic resonance imaging to a standard atlas confirmed the location of the recording cylinder over the lateral bank of the intraparietal sulcus, using CARET software.

“Comparison of a postoperative magnetic resonance imaging (Fig. 1) to a standard atlas confirmed the location of the recording cylinder over the lateral bank of the intraparietal sulcus, using CARET software”

• cites Van Essen et al., 2001Not checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing).

Five neurons failed to exhibit selectivity on the initial discrimination test and were excluded from additional testing.

“Five neurons failed to exhibit selectivity on this test and were excluded from additional testing.”

May combine two claims.

Pulse and nonpulse trials were not obviously different in appearance, and the perturbations were controlled independently of the random dot motion display.

“Thus, pulse and nonpulse trials were not obviously different in appearance, and these perturbations were controlled independently of the random dot motion display.”

Classified as probably not a substantial claim.

Neural activity in the lateral intraparietal area (LIP) of the monkey brain reflects the formation of perceptual decisions in a random dot direction-discrimination task in which monkeys communicate their decisions with eye-movement responses.

“Previous work has suggested that neural activity in the lateral intraparietal area (LIP) of the monkey brain reflects the formation of perceptual decisions in a random dot direction-discrimination task in which monkeys communicate their decisions with eye-movement responses.”

• cites Shadlen and Newsome, 2001Not checked yet

  Not checked in the free run.

• cites Roitman and Shadlen, 2002Not checked yet

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Classified as probably not a substantial claim. May combine two claims.

The transitions from random modulation to a motion pulse and back to random modulation were seamless, with no change in mean luminance or average contrast.

“Importantly, the transitions from random modulation to a motion pulse (and back to random modulation) were seamless: the change in motion was not associated with a change in mean luminance or average contrast.”

Classified as probably not a substantial claim.

The responses of middle temporal (MT) neurons reflect the direction and strength of the motion signal.

“Previous work has shown that the responses of middle temporal (MT) neurons reflect the direction and strength of the motion signal”

• cites Britten et al., 1993Not checked yet

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• cites Britten and Newsome, 1998Not checked yet

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May combine two claims.

Decision-related LIP responses, behavioral choices, and reaction times can be explained by near-perfect time integration that stops when a criterion amount of evidence has been accumulated.

“Additional analyses suggest that decision-related LIP responses, as well as behavioral choices and reaction times, can be explained by near-perfect time integration that stops when a criterion amount of evidence has been accumulated.”

• Also stated in: § Introduction · hedged

  “Our analyses suggest that LIP activity and psychophysical behavior may reflect near-perfect temporal integration of motion signals until a criterion amount of evidence in favor of one decision has been accumulated.”

• AssumptionThe authors state this as an assumption: The motion strength biases the diffusion of a state variable, effectively the accumulated evidence for one direction and against the other, toward one absorbing boundary.
• AssumptionThe authors state this as an assumption: The decision terminates when the state variable reaches one of the absorbing boundaries at ±A.
• AssumptionThe authors state this as an assumption: In a time increment dt, the state variable changes by a random increment drawn from a Gaussian distribution with mean dt and variance dt.
• AssumptionThe authors state this as an assumption: When there is no net motion, there is no bias to the diffusion, so the process has an equal probability of stopping at the +A or -A bound.
• AssumptionThe authors state this as an assumption: The mean reaction time is the decision time plus the mean of an independent nondecision time that is not affected by motion strength or direction.
• AssumptionThe authors state this as an assumption: The drift bias is proportional to the signed motion coherence, with the sign of coherence indicating the direction of motion.
• AssumptionThe authors state this as an assumption: The effect of the background motion pulse can be represented as an equivalent change in motion strength.

May combine two claims.

Most recorded neurons were encountered 3-7 mm below the pia mater along a trajectory approximately parallel to the intraparietal sulcus and most likely corresponded to the posterior two-thirds of ventral LIP.

“Most neurons we recorded from were encountered 3-7 mm below the pia mater along a trajectory that ran approximately parallel to the intraparietal sulcus and most likely corresponded to the posterior two-thirds of ventral LIP”

• cites Lewis and Van Essen, 2000Not checked yet

  Not checked in the free run.

May combine two claims.

The population of LIP neurons reflects the combination of both dot and texture motions, and the effect shown in the population average is representative of the effects in individual neurons.

“This analysis indicates that the population of LIP neurons reflects the combination of both dot and texture motions, and that the effect shown in the population average (Fig. 6) is representative of the effects in individual neurons.”

Classified as probably not a substantial claim.

The response-template subtraction strategy allows isolation of the effect of a pulse as a deviation in spike rate from the level that occurs as a function of motion, choice, and time.

“This strategy allows us to isolate the effect of a pulse, expressed in terms of a deviation in spike rate from the level that occurs as a function of motion, choice, and time.”

Probably not a substantial claim: may not pass S3 (load-bearing).

The results do not change appreciably if both types of excluded trials are included in the analyses, including estimates of the temporal persistence of pulse effects.

“Our results do not change appreciably if both types of excluded trials are included in our analyses, including our estimates of the temporal persistence of pulse effects.”

May combine two claims.

Pulses shifted the RTs subtly but systematically, as if a small amount of motion from the pulse was added to, or subtracted from, the stream of motion information supplied by the dynamic random dots.

“Indeed, pulses shifted the RTs subtly but systematically, as if a small amount of motion from the pulse was added to, or subtracted from, the stream of motion information supplied by the dynamic random dots.”

May combine two claims.

LIP spike rates and psychophysical choices reflect substantial temporal integration of visual motion.

“our results demonstrate that both LIP spike rates and psychophysical choices reflect substantial temporal integration of visual motion: brief pulses of motion exert effects that persist for several hundreds of milliseconds.”

• Also stated in: § Additivity and time-shift invariance of integration · boosted

  “At present, our results demonstrate that LIP spike rates reflect substantial temporal integration.”

• Also stated in: § Discussion · plain

  “Our experimental findings show that LIP neurons represent the time integral of motion evidence but lend little insight into the mechanism underlying the integration process.”

May combine two claims.

Both the speed and accuracy of decisions depended on a simple combination of random dot and texture motions.

“Together, these results suggest that both the speed and accuracy of decisions depended on a simple combination of random dot and texture motions.”

• AssumptionThe authors state this as an assumption: For all motion strengths and pulse conditions, the height of the decision bounds, the constant of proportionality from motion strength to momentary evidence, and the mean nondecision time are common.

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Although some model parameters were adjusted to fit aspects of the data, they did not directly determine the degree of temporal persistence in the model; the model posits perfect, but bounded, integration.

“It is important to note that, although some of the parameters were adjusted to fit various aspects of the data, they did not directly determine the degree of temporal persistence in the model: the model posits perfect, but bounded, integration.”

May combine two claims.

The latencies and time courses of pulse effects were not closely linked to immediate behavioral responses, and the pulses did not tend to exert fleeting effects on individual trials.

“This demonstrates that the latencies and time courses of pulse effects were not closely linked to immediate behavioral responses and argues against the idea that the pulses tended to exert fleeting effects on individual trials.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The model has been described in detail previously and was shown to account for the major psychophysical and physiological results in an unperturbed version of the RT direction-discrimination task.

“This model has been described in detail previously and was shown to account for the major psychophysical and physiological results in an unperturbed version of the RT direction-discrimination task (Mazurek et al., 2003) (see Materials and Methods).”

• cites Mazurek et al., 2003Not checked yet

  Not checked in the free run.

May combine two claims.

Leak can decrease the temporal persistence of pulse effects, but it should not preferentially affect the strength of pulses that occur later in time.

“Although leak can decrease the temporal persistence of pulse effects, it should not preferentially affect the strength of pulses that occur later in time.”

May combine two claims.

Our results provide clear psychophysical and physiological support for a temporal integration mechanism, and they are inconsistent with alternative mechanisms that do not rely on temporal integration.

“Our results provide clear psychophysical and physiological support for such a temporal integration mechanism, and they are inconsistent with alternative mechanisms that do not rely on temporal integration.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Previous studies of LIP responses in other tasks have identified signals that are not immediately linked to incoming sensory stimuli or to the execution of motor actions.

“Previous studies of LIP responses in other tasks have identified signals that are not immediately linked to incoming sensory stimuli or to the execution of motor actions.”

• cites Gnadt and Andersen, 1988Not checked yet

  Not checked in the free run.

• cites Mazzoni et al., 1996Not checked yet

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• cites Snyder et al., 1997Not checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

Dip-and-rise response profiles with similar latencies have been reported in other tasks and brain areas in which they also appear to signal the beginning of a cognitive process.

“Interestingly, dip-and-rise response profiles with similar latencies have been reported in other tasks and brain areas (Sato and Schall, 2001;Leon and Shadlen, 2003) in which they also appear to signal the beginning of a cognitive process.”

• cites Sato and Schall, 2001Not checked yet

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• cites Leon and Shadlen, 2003Not checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing).

Persistent activity in LIP can represent graded levels of accumulated evidence.

“Preliminary observations using a discrete and sequential presentation of evidence suggest that persistent activity in LIP can represent graded levels of accumulated evidence (Yang and Shadlen, 2004).”

• cites Yang and Shadlen, 2004Not checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing).

Once LIP activity reaches a decision bound, another ~100-150 ms are required to execute the motor response.

“Once LIP activity reaches a decision bound, another ϳ100 -150 ms are required to execute the motor response (Colby et al., 1996;Roitman and Shadlen, 2002).”

• cites Colby et al., 1996Not checked yet

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• cites Roitman and Shadlen, 2002Not checked yet

  Not checked in the free run.

Classified as probably not a substantial claim.

Oculomotor integrator neurons maintain graded levels of activity to represent different gaze positions.

“Oculomotor integrator neurons are able to maintain graded levels of activity to represent different gaze positions”

• cites Cannon et al., 1983Not checked yet

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• cites Cannon and Robinson, 1985Not checked yet

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• cites Arnold and Robinson, 1991Not checked yet

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May combine two claims.

The order of these effects suggests that LIP activity does not reflect a postdecision feedback signal representing a choice that has already occurred but more likely reflects the ongoing computations during the formation of decisions.

“The order of these effects suggests that LIP activity does not reflect a postdecision feedback signal representing a choice that has already occurred but more likely reflects the ongoing computations during the formation of decisions.”

Probably not a substantial claim: may not pass S3 (load-bearing).

LIP has been implicated in spatial working memory, motor planning, and the allocation of spatial attention.

“Thus, LIP has been implicated in a variety of higher functions, including spatial working memory, motor planning, and the allocation of spatial attention (Gnadt and Andersen, 1988;Mazzoni et al., 1996;Snyder et al., 1997;Gottlieb et al., 1998;Ciaramitaro et al., 2001;Pare ´ and Wurtz, 2001;Bisley and Goldberg, 2003;Zhang and Barash, 2004).”

• cites Gnadt and Andersen, 1988Not checked yet

  Not checked in the free run.

• cites Mazzoni et al., 1996Not checked yet

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• cites Snyder et al., 1997Not checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

If LIP neurons are relaying the result of a neural computation performed elsewhere, they appear to mirror the computation with great fidelity, because the LIP responses bear an uncanny resemblance to the signals that govern choice and RT.

“If the latter, then they appear to mirror the computation with great fidelity, because the LIP responses bear an uncanny resemblance to the signals that govern choice and RT.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Human subjects are capable of adjusting the decision bound to implement a desired balance between speed and accuracy in the direction-discrimination task.

“Human subjects are capable of adjusting the decision bound to implement a desired balance between speed and accuracy in the direction-discrimination task (Palmer et al., 2005).”

• cites Palmer et al., 2005Not checked yet

  Not checked in the free run.

May combine two claims.

Motion pulses affect LIP response with a latency of 225 ms, suggesting that LIP does not ignore the first 200-225 ms of random dot motion but instead lags the visual stimulus by ~225 ms.

“The finding here that motion pulses affect LIP response with a latency of 225 ms suggests that LIP does not ignore the first 200 -225 ms of random dot motion but instead lags the visual stimulus by ϳ225 ms.”

May combine two claims.

Memory-less mechanisms are incompatible with the findings in our study because brief perturbations affect behavior and the neural response over a prolonged interval.

“They are incompatible with the findings in our study because brief perturbations affect behavior and the neural response over a prolonged interval.”

Probably not a substantial claim: may not pass S3 (load-bearing).

A large class of decision-making models posit some form of temporal integration, including accumulator, random walk, diffusion, and a variety of nonstationary and hybrid models.

“A large class of decision-making models posit some form of temporal integration, including accumulator (LaBerge, 1962;Audley and Pike, 1965;Vickers, 1970), random walk (Stone, 1960;Link, 1975;Link and Heath, 1975;Laming, 1979), diffusion (Ratcliff, 1978;Ratcliff et al., 2003), and a variety of nonstationary and hybrid models (Smith, 1995(Smith, , 2000;;Usher and McClelland, 2001;Ditterich, 2005).”

• cites LaBerge, 1962Not checked yet

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• cites Audley and Pike, 1965Not checked yet

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• cites Vickers, 1970Not checked yet

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Probably not a substantial claim: may not pass S3 (load-bearing).

In simple detection tasks, linear accumulation of signal plus variance is often restricted to very short durations, under 80 ms.

“In simple detection tasks, for example, linear accumulation of signal plus variance is often restricted to very short durations, under 80 ms (Watson, 1986).”

• cites Watson, 1986Not checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing).

All curves in both panels are described by a single fit of Equations 6 and 7 to all points in both panels.

“All curves in both panels are described by a single fit of Equations 6 and 7 to all points in both panels.”

Probably not a substantial claim: may not pass S3 (load-bearing).

A common feature of LIP responses in many experimental contexts is a persistent change in neural activity that is triggered by a sensory cue but does not simply depend on the visual presence or absence of that cue.

“For example, a common feature of LIP responses in many experimental contexts is a persistent change in neural activity that is triggered by a sensory cue but does not simply depend on the visual presence or absence of that cue.”

• cites Gnadt and Andersen, 1988Not checked yet

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• cites Mazzoni et al., 1996Not checked yet

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• cites Snyder et al., 1997Not checked yet

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Probably not a substantial claim: may not pass S2 (checkable), S4 (based).

The temporal integration we have identified may underlie the flexible combination or comparison of multiple pieces of sensory evidence that occur at different times but are all relevant to a common decision or action.

“The temporal integration we have identified may underlie the flexible combination or comparison of multiple pieces of sensory evidence that occur at different times but that are all relevant to a common decision or action.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Even in contexts where time integration alone cannot account for LIP functions, temporal integration may facilitate the incorporation of various types of information into neural computations over a flexible and extended time frame.

“However, even in these contexts, temporal integration may facilitate the incorporation of these various types of information into neural computations that occur over a more flexible and extended time frame.”

Probably not a substantial claim: may not pass S3 (load-bearing).

Our results do not immediately allow us to distinguish between competing accounts of LIP function.

“our results do not immediately allow us to distinguish between competing accounts of LIP function”