Transformation of perception from sensory to motor cortex

“When a judgement must be made about a single noisy stimulus, evidence can be accumulated over time [21, 22].”

“We represented population dynamics as high-dimensional trajectories in neuronal activity space [17] and identified the angle that maximizes variation in projection length as a function of sp1; projection length is then an estimate of population mean speed signal.”

“The present work is consistent with the notion that the posterior-to-anterior transformation of information in the cerebral cortex is accompanied by a broadening of the timescale by which neurons encode sensory events [28, 29].”

“The present work is consistent with the notion that the posterior-to-anterior transformation of information in the cerebral cortex is accompanied by a broadening of the timescale by which neurons encode sensory events [28, 29].”

“Cortical Encoding of the Whisker Vibration In the remainder of this article, we examine neuronal activity in behaving rats from two regions (Figure S4)—vS1, the main entryway of sensory signals to the cerebral cortex [11, 12], and vM1, the target of projections from sensory cortical regions and a source of dense proje…”

“When a judgement must be made about a single noisy stimulus, evidence can be accumulated over time [21, 22].”

“For instance, when rats [3] or monkeys [4] were required to report the presence of a tactile stimulus around the detection threshold, sensory cortical activity varied little across trials, whereas the triggering of all-or-none activity cascades in frontal cortex correlated with awareness of the stimulus [5].”

“A very small set of vS1 neurons showed this property, perhaps reflecting frontal cortex feedback to vS1 [15].”

“In the intervening years, investigators have exploited ever-improving techniques to reinforce the notion that intracortical processing is critical to perceptual functions [2].”

“Thus, vM1 participates in multiple steps of the task, similar to ventral premotor cortex and dorsolateral prefrontal cortex in monkeys [4, 25] and consistent with a prominent role in action selection [26, 27].”

“Thus, vM1 participates in multiple steps of the task, similar to ventral premotor cortex and dorsolateral prefrontal cortex in monkeys [4, 25] and consistent with a prominent role in action selection [26, 27].”

“Time dependence has been reported in monkeys in loudness judgement [18] and tactile flutter frequency discrimination [10] and in humans for luminance and loudness judgment [19, 20].”

“1588 Current Biology 27, 1585–1596, June 5, 2017 Perceived Intensity Is Accounted for by Nonlinear Summation of Instantaneous Speed What form of integration leads to the perceptual judgements reported above? Because earlier work argued for a greater contribution of the early response in primary somatosensory cortex [1…”

“This might be an outcome of adaptation, whereby neurons’ firing rates decrease as vibrations are extended in time [16].”

“Thus, vM1 participates in multiple steps of the task, similar to ventral premotor cortex and dorsolateral prefrontal cortex in monkeys [4, 25] and consistent with a prominent role in action selection [26, 27].”

“Brain regions we have not studied here, such as secondary vibrissal sensory cortex (vS2), posterior parietal cortex, and other frontal cortical areas may also play important roles, as in monkeys [4].”

“Cortical Encoding of the Whisker Vibration In the remainder of this article, we examine neuronal activity in behaving rats from two regions (Figure S4)—vS1, the main entryway of sensory signals to the cerebral cortex [11, 12], and vM1, the target of projections from sensory cortical regions and a source of dense proje…”

“For instance, when rats [3] or monkeys [4] were required to report the presence of a tactile stimulus around the detection threshold, sensory cortical activity varied little across trials, whereas the triggering of all-or-none activity cascades in frontal cortex correlated with awareness of the stimulus [5].”

“Subjects were required to compare the intensities of two vibrations—stimulus 1 of duration T1 and stimulus 2 of duration T2—separated by a delay of 2 s (Figure 1B) [6].”

“Time dependence has been reported in monkeys in loudness judgement [18] and tactile flutter frequency discrimination [10] and in humans for luminance and loudness judgment [19, 20].”

“Cortical Encoding of the Whisker Vibration In the remainder of this article, we examine neuronal activity in behaving rats from two regions (Figure S4)—vS1, the main entryway of sensory signals to the cerebral cortex [11, 12], and vM1, the target of projections from sensory cortical regions and a source of dense proje…”

“In 1979, Whitfield [1] surveyed the first century of neuroscience and pointed to clear evidence that, after ablation of sensory and association regions of cerebral cortex, animals can still perform many forms of sensory discrimination.”

“Time dependence has been reported in monkeys in loudness judgement [18] and tactile flutter frequency discrimination [10] and in humans for luminance and loudness judgment [19, 20].”

“The Neuronal Correlate of Perceived Intensity Resides in vM1 and Not in vS1 In tasks where rodents discriminate sequences of discrete whisker deflections, vS1 neurons fail to show substantial temporal integration [23, 24].”

“Cortical Encoding of the Whisker Vibration In the remainder of this article, we examine neuronal activity in behaving rats from two regions (Figure S4)—vS1, the main entryway of sensory signals to the cerebral cortex [11, 12], and vM1, the target of projections from sensory cortical regions and a source of dense proje…”

“In such paradigms, prominent delay-period activity has been reported in many cortical areas (Chabrol et al., 2019; Chen et al., 2017; Erlich et al., 2011; Esmaeili and Diamond, 2019; Fassihi et al., 2017; Funahashi et al., 1989; Fuster and Alexander, 1971; Gilad et al., 2018; Guo et al., 2014; Li et al., 2015; Makino…”

“For example, rats have been trained to make decisions informed by multiple sensory modalities [35], to accumulate evidence almost perfectly over long periods of time [11], and to compare and report the intensity of two vibrations separated by a delay [36].”

“, 2014, 2017), or duration (Fassihi et al., 2017) of two vibrations].”

“, 2000) and the processing of tactile (Diamond et al., 2008; Fassihi et al., 2017; Zuo and Diamond, 2019) and olfactory (Chae et al.”

“Overall, perceptual judgements emerge from the temporal integration of sensory inputs downstream of primary sensory cortices [9].”

“These results should enable optogenetic manipulations of cortical regions, including vibrissal motor cortex (Fassihi et al., 2017), starting from basic knowledge of their functional properties.”

“Neurons in rat somatosensory cortex precisely encode instantaneous speed [7], and analogous coding mechanisms exist in primates [10].”

“, 2017) and primary motor cortex (M1) (Fassihi et al., 2017).”

“Moreover, activity in vM1 is more similar to the perceived stimulus than the activity in vS1 (Fassihi et al., 2017; Mongillo and Loewenstein, 2017).”

“This finding is consistent with a study by Fassihi et al. (2017), in which an extended vibratory stimulus was integrated between S1 and wMC (Fassihi et al., 2017).”

“…which pairs of stimuli should benefit from a better performance and which should suffer, but does not explain the gradual accumulation of errors upon increasing (decreasing) s 1 , for pairs below (above) the s 1 = s 2 diagonal ( Fassihi et al., 2014 ; Fassihi et al., 2017 ; Akrami et al., 2018 ).”

“In agreement with earlier work suggesting a vS1 role in the neuronal representation of vibration intensity 13,20 , fi ring rates were higher for greater intensity vibrations.”

“Furthermore, frontoparietal regions are relevant to encoding vibrotactile stimuli (Woolgar and Zopf, 2017) (see also, Godde et al., 2010, Wu et al., 2018, Fassihi et al., 2017, Ku et al., 2007, Soros et al., 2007).”

“In adult rodents, intense interactions between primary somatosensory cortex barrel field (S1Bf), secondary somatosensory (S2), and motor cortex (M1) are necessary for adequate detection and perception of tactile stimuli (Fassihi et al., 2017; Petersen, 2019), and”

“Our model for the afferent inputs to the RNN units is inspired by physiological recordings from Arabzadeh et al. [30] and Fassihi et al. [31] of the primary vibrissal somatosensory cortex (VS1).”

“Because rat sensory cortical neurons robustly encode speed but not velocity (Fassihi et al 2017), we may also consider the stimulus as a sequence of speed values drawn from a half-Gaussian distribution.”

“participants performing a similar task (vibrotactile stimulation to the finger) [8].”

“Comparable findings of longer information consistency timescales in association or decision areas, with respect to sensory areas, have been reported in tactile discrimination experiments (Fassihi et al. 2017).”

“Comparable findings of longer information consistency timescales in association or decision areas, with respect to sensory areas, have been reported in tactile discrimination experiments [100].”

“…von Heimendahl et al., 2007; O'Connor et al., 2010; Miyashita and Feldman, 2012; Feldmeyer et al., 2013; Guo et al., 2014a; Burgess et al., 2017; Fassihi et al., 2017; Chakrabarti and Schwarz, 2018; Hong et al., 2018; Odoemene et al., 2018; Ryan et al., 2022; Waiblinger et al., 2022; Diamond…”

“PP�kk(ii)�tt� = ffrr ii(tt)kkii ee−ffrr (ii)(tt) kk! (5)”

“…delay period activity in broad regions of frontal cortex (Chabrol et al., 2019; Chen et al., 2017; Erlich et al., 2011; Esmaeili and Diamond, 2019; Fassihi et al., 2017; Funahashi et al., 1989; Fuster and Alexander, 1971; Guo et al., 2014; Li et al., 2015; Makino et al., 2017; Tanji and Evarts,…”

“…cortical relay for whisker kinematics, while vM1 – a main frontal target of vS1 ( 28 – 32 ) – contains whisker-encoding neurons ( 28 , 29 ) and is involved in sensorimotor control ( 33 , 34 ), orienting ( 35 – 37 ), delayed responding ( 37 , 38 ), and perceptual decision-making ( 39 , 40 , 29 ).”

“Evidence of this bias has been described across various domains: in the auditory system (Akrami et al., 2018; Raviv et al., 2014), the visual system (Olkkonen et al., 2014) and the somatosensory system (Fassihi et al., 2017).”

“Within the vibrissal sensory cortex of rodents, the perceived intensity of oscillatory stimuli grows over the course of longer stimulus durations [47].”

“Serial transformation of sensory inputs along bottom–up hierarchical pathways has been observed in rodents engaged in whisker-discrimination tasks (8, 9) with an increasingly stronger association with perceptual choice in S2 (10, 11) and premotor areas (12–14) rather than whisker-related wS1 (9).”

“The brain adapts by engaging regions suited for prolonged accumulation and informed decision-making (von Heimendahl et al., 2007; Zuo et al., 2011; Estebanez et al., 2012; Fassihi et al., 2017, 2020; Zuo and Diamond, 2019a,b).”

“Within a trial, intensity and duration influenced each other bidirectionally: stronger stimuli felt longer and longer stimuli felt stronger, replicating previous work in humans and rodents 14,29,31,32,36 .”

“Fassihi et al. (2017) showed that neuronal activities after stimulus offset in vM1 (vibrissal motor cortex) but not vS1 (vibrissal sensory cortex) is modulated by both the speed and duration of tactile vibration.”

“9 time [31] and acts as a goal-directed modulator or inhibitor, rather than just a generator, of motor actions [32].”

“This strategy is also found in rats and humans performing a tactile noise discrimination task [19] and monkeys performing discrimination of fingertip vibrotactile stimuli [20], pointing to a possible general principle.”