The effects of early life stress on reward processing

In the paper

“dopamine from the nucleus accumbens is important for the ability of rewarding cues to gain incentive salience and elicit instrumental behavior (Peciña et al., 2003; Wyvell and Berridge, 2000).”

What the sources say

• Partly supported

  The Introduction says dopamine systems may increase the incentive value of reward stimuli, and the ‘Dopamine enhances wanting for sweet rewards’ section links elevated dopamine to more eager, direct runway behavior. The paper does not establish that dopamine specifically from the nucleus accumbens produces these effects: its DAT knockdown is not restricted to that region. (LLM, conf=0.85)

  cites Peciña et al., 2003 sourceExperimental — accuracy not yet measured
• Not checked yetcites Wyvell and Berridge, 2000

In the paper

“This is an important concept in the field of addiction (Burke and Miczek, 2014b; George et al., 2012; Sinha, 2008), that is hypothesized to mediate the relationship between ELS and increased risk of substance use disorders (Andersen and Teicher, 2009).”

What the sources say

• Not checked yetcites Burke and Miczek, 2014b
• Supported

  George et al. is cited for the first clause: that the concept is important in addiction. The Allostasis section describes allostasis as a framework for understanding vulnerability to drug addiction. The separate hypothesis about early-life stress is cited to Andersen and Teicher, not George et al. (LLM, conf=0.87)

  cites George et al., 2012 source
• Supported

  Sinha (2008) is cited for the first clause: that the link is an important concept in addiction. The “Stress and the Development of Addictive Behaviors” section says major addiction theories assign stress an important role. The mediation hypothesis in the second clause is cited to Andersen and Teicher (2009), not Sinha. (LLM, conf=0.90)

  cites Sinha, 2008 source

In the paper

“Other factors, such as sex of animal or duration/length of separation, did not account for variation in results.”

In the paper

“In one frequently cited study in marmoset monkeys, daily bouts of isolation from parents for the first month of life resulted in unchanged free consumption of a sweet solution at seven months, but decreased effort expenditure on a progressive reinforcement schedule (Pryce et al., 2004).”

What the sources say

• Not checked yetcites Pryce et al., 2004 source

In the paper

“Deficits in the ability to alter behavior based on changing reward cues, known as reversal learning, have also been reported with parental deprivation in monkeys (Pryce et al., 2004) and maternal separation in rats (Matthews et al., 1996a).”

What the sources say

• Not checked yetcites Pryce et al., 2004 source
• Not checked yetcites Matthews et al., 1996a

In the paper

“Maternal separation was also associated with decreased conditioned locomotor activity to food-related cues (Matthews et al., 1996b, 1996a) as well as decreased conditioned place preference to chocolate (Sasagawa et al., 2017) indicative of a decreased reward valuation/incentive salience function within the approach motivation construct.”

What the sources say

• Not checked yetcites Matthews et al., 1996b
• Not checked yetcites Matthews et al., 1996a
• Not checked yetcites Sasagawa et al., 2017 source

In the paper

“Changes to the opioid system are also apparent with maternal separation, but conflicting results also exist based on specific methodology, demonstrating both increases and decreases in levels of endogenous peptides (Ploj et al., 2003; Vazquez et al., 2005) as well as sensitivity to ligands (Kalinichev et al., 2001; Vazquez et al., 2005).”

What the sources say

• Not checked yetcites Ploj et al., 2003 source
• Not checked yetcites Vazquez et al., 2005 source
• Not checked yetcites Kalinichev et al., 2001 source

In the paper

“Several studies found that while maternal separation by itself did not result in changes in sucrose preference, occurrence of a second stressor or challenge in adolescence or adulthood resulted in reduced sucrose preference (Hill et al., 2014; Klug and van den Buuse, 2012; Uchida et al., 2010).”

What the sources say

• Not checked yetcites Hill et al., 2014 source
• Not checked yetcites Klug and van den Buuse, 2012
• Not checked yetcites Uchida et al., 2010 source

In the paper

“there are data showing that cognitive remediation, including working memory training and mindfulness, can enhance reward processing in non-clinical populations with high trait social anhedonia (Li et al., 2016) and in prescription opioid abusers (Garland, 2016).”

What the sources say

• Not checked yetcites Li et al., 2016
• Not checked yetcites Garland, 2016 source

In the paper

“Data were extracted by no fewer than two separate authors to ensure accuracy and limit bias (Tables 1, 2).”

In the paper

“Deficits in reward processing are found in MDD (Admon and Pizzagalli, 2015), substance use disorders (Garfield et al., 2014; Tobler et al., 2016), posttraumatic stress disorder (PTSD) (Kalebasi et al., 2015), schizophrenia (McCarthy et al., 2016), and ADHD (van Hulst et al., 2016).”

What the sources say

• Not checked yetcites Admon and Pizzagalli, 2015 source
• Not checked yetcites Garfield et al., 2014 source
• Not checked yetcites Tobler et al., 2016 source

In the paper

“individuals with MDD have similar hedonic responses to sweet solutions compared to controls (Berlin et al., 1998), but are less likely to engage in tasks requiring higher amounts of effort (Treadway et al., 2012).”

What the sources say

• Not checked yetcites Berlin et al., 1998 source
• Not checked yetcites Treadway et al., 2012 source

In the paper

“The particular psychopathological trajectory might depend on the type of ELS (Carr et al., 2013) and the developmental window in which the stress was experienced (Andersen et al., 2008), as well as genetic and epigenetic risk and protective factors (Caspi et al., 2003; Palma-Gudiel and Fañanás, 2016).”

What the sources say

• Not checked yetcites Carr et al., 2013 source
• Not checked yetcites Andersen et al., 2008
• Not checked yetcites Caspi et al., 2003 source

In the paper

“Early life stress has been found to both exaggerate and attenuate the activity of the HPA axis in response to stress, both phenomena which have been linked to psychopathology (Carpenter et al., 2009; Heim C et al., 2000; Tyrka et al., 2008).”

What the sources say

• Not checked yetcites Carpenter et al., 2009 source
• Not checked yetcites Heim C et al., 2000 source
• Not checked yetcites Tyrka et al., 2008 source

In the paper

“receptors for CRF and glucocorticoids are located throughout the reward circuitry of the brain, with their activation or blockade affecting reward-sensitive neurotransmission and behaviors (Bryce and Floresco, 2016; Craenenbroeck et al., 2005; Walsh et al., 2014).”

What the sources say

• Not checked yetcites Bryce and Floresco, 2016
• Not checked yetcites Craenenbroeck et al., 2005 source
• Not checked yetcites Walsh et al., 2014 source

In the paper

“This overlap between stress neurobiology and reward neurobiology suggests that any change in stress neurobiology is likely to influence reward.”

In the paper

“However, animal models cannot replicate the complexity of human ELS, and the significance of findings for human conditions is not always clear.”

In the paper

“It should be noted that parsing of various reward processes using the RDoC framework is limited by the precision of the paradigm used, with several paradigms engaging more than one process.”

In the paper

“Even in individuals who do not meet full diagnostic criteria, alterations in reward processing predict later diagnoses of MDD (Nelson et al., 2016), substance use disorder (Castellanos-Ryan et al., 2011; Garfield et al., 2014), and conduct disorder (Rubia et al., 2009).”

What the sources say

• Not checked yetcites Nelson et al., 2016 source
• Not checked yetcites Castellanos-Ryan et al., 2011 source
• Not checked yetcites Rubia et al., 2009 source

In the paper

“Variability and co-variation of these factors represent a major challenge in human studies.”

In the paper

“Antagonism of dopamine receptors or dopamine depletion in the ventral striatum (specifically the nucleus accumbens) reduce the amount of effort an animal will expend to obtain a reward, but often leave intact reward consumption and positive hedonic responses (e.g., affective facial expressions) (Berridge and Robinson, 1998; Salamone and Correa, 2002).”

What the sources say

• Not checked yetcites Berridge and Robinson, 1998 source
• Not checked yetcites Salamone and Correa, 2002 source

In the paper

“Maternal separation interferes with the postnatal regulatory influence that the mother has on the animal’s physiology and development, and is considered by many to be an analog of human child neglect (Carlyle et al., 2012; Pryce et al., 2005).”

What the sources say

• Not checked yetcites Carlyle et al., 2012 source
• Not checked yetcites Pryce et al., 2005

In the paper

“Responsiveness to reward also involves the nucleus accumbens (in addition to other regions, such as the ventral pallidum), but opioids and endocannabinoids are the major neurochemical mediators of reward responsiveness (Mahler et al., 2007; Peciña and Berridge, 2005).”

What the sources say

• Not checked yetcites Mahler et al., 2007 source
• Not checked yetcites Peciña and Berridge, 2005

In the paper

“Thus, dopamine in the nucleus accumbens appears to be necessary for the approach motivation aspects of reward processing, but is less involved in the hedonic experience/initial responsiveness to reward.”

In the paper

“development of the human brain is protracted compared to other species (Clancy et al., 2001; Miller et al, 2012; Semple et al., 2013), so despite having a more “mature” brain at birth compared to rats, vulnerability to insult remains.”

What the sources say

• Not checked yetcites Clancy et al., 2001 source
• Not checked yetcites Miller et al, 2012 source
• Not checked yetcites Semple et al., 2013 source

In the paper

“One of the most common uses of the sucrose preference test is to assess stress-induced anhedonia in animal models of depression, where reduced consumption of sucrose is considered indicative of depressive-like behavior (Willner et al., 1996).”

What the sources say

• Not checked yetcites Willner et al., 1996 source

In the paper

“The reward prediction error, in which changes in dopamine firing encode differences between an expected vs. actual reward outcome, allows for dynamic learning from experience and updates in reward expectations (Gradin et al., 2011; Schultz, 2016).”

What the sources say

• Not checked yetcites Gradin et al., 2011 source
• Not checked yetcites Schultz, 2016 source

In the paper

“Because most components of reward processing are ultimately subjective phenomena (motivation, hedonic experience), their occurrence in animals can only be inferred by the measurement of behavior.”

In the paper

“the most common manipulations in animals to model ELS consist of maternal and peer separation.”

In the paper

“It is in this circuit that information about reward cues, reward value, and required effort is processed, communicated, and then integrated to guide decision-making, facilitate motivation and readiness for action, and eventually result in the experience of pleasure (Rizvi et al., 2016) (Figure 2).”

What the sources say

• Not checked yetcites Rizvi et al., 2016 source

In the paper

“Within the PFC, the orbital frontal cortex encodes and maintains reward value, while the anterior cingulate cortex plays a role in monitoring and determining effort required to obtain rewards (for review see (Rushworth et al., 2011)).”

What the sources say

• Not checked yetcites Rushworth et al., 2011 source

In the paper

“Such reversal is known to depend on an intact orbitofrontal cortex to inhibit the prior learned response (Placek et al., 2013; Rolls, 2016).”

What the sources say

• Not checked yetcites Placek et al., 2013 source
• Not checked yetcites Rolls, 2016 source

In the paper

“Observation of orofacial movements is probably the only measure of liking independent of any learning or motivational process (Berridge and Robinson, 1998), but this is rarely studied.”

What the sources say

• Not checked yetcites Berridge and Robinson, 1998 source

In the paper

“conditioned place preference can be conceptualized as probing the “reward valuation” subconstruct within approach motivation, but expectancy is arguably also involved, given the presence of Pavlovian conditioned approach behavior (Flagel et al., 2009; NIMH Research Domain Criteria).”

What the sources say

• Not checked yetcites Flagel et al., 2009 source
• Not checked yetcites NIMH Research Domain Criteria

In the paper

“regions of the prefrontal cortex (PFC) and amygdala are additional key brain areas involved in reward circuitry.”

In the paper

“Reward value and deviations of expected and actual outcomes are encoded via the amygdala through its projections to the PFC (Lichtenberg et al., 2017; Wassum and Izquierdo, 2015).”

What the sources say

• Not checked yetcites Lichtenberg et al., 2017 source
• Not checked yetcites Wassum and Izquierdo, 2015

In the paper

“While there are multiple well-validated tests of reward behavior in animals that allow some differentiation between various reward processing components, close scrutiny often reveals that more than one component is likely involved.”

In the paper

“Dopamine signaling to the basal ganglia, including the nucleus accumbens, also plays a role in what is known as the reward prediction error, a subconstruct of approach motivation.”

What the sources say

• Not checked yetcites Gradin et al., 2011 source
• Not checked yetcites Schultz, 2016 source

In the paper

“Thus, stressors occurring earlier in life might be more likely to affect subcortical reward functions (approach motivation and reward responsiveness), with those later in adolescence more likely affecting learning, valuation, and effort prediction.”

In the paper

“Normative development of the brain regions involved in reward processing demonstrates structural and functional changes from childhood to adulthood, with maturation of PFC regions typically delayed compared to that of subcortical regions (Galvan et al., 2006; Mills et al., 2014; Somerville et al., 2011).”

What the sources say

• Not checked yetcites Galvan et al., 2006 source
• Not checked yetcites Mills et al., 2014 source
• Not checked yetcites Somerville et al., 2011 source

In the paper

“The conditioned place preference task is thought to measure incentive motivation to seek out cues previously associated with reward (Bardo and Bevins, 2000).”

What the sources say

• Not checked yetcites Bardo and Bevins, 2000

In the paper

“While pre-weaning maternal separation is often conceptualized as early life neglect and results in a depressive-like phenotype (Pryce et al., 2005), post-weaning social isolation during the juvenile and adolescent period produces sensory processing deficits and increases in fear and anxiety-like behavior (Fone and Porkess, 2008; Lukkes et al., 2009).”

What the sources say

• Not checked yetcites Fone and Porkess, 2008
• Not checked yetcites Lukkes et al., 2009 source

In the paper

“While pre-weaning maternal separation is often conceptualized as early life neglect and results in a depressive-like phenotype (Pryce et al., 2005), post-weaning social isolation during the juvenile and adolescent period produces sensory processing deficits and increases in fear and anxiety-like behavior (Fone and Porkess, 2008; Lukkes et al., 2009).”

What the sources say

• Not checked yetcites Pryce et al., 2005

In the paper

“The neonatal rat relies upon the dam for protection from predators, nutrition, thermoregulation, and proper elimination of waste (Hofer, 1996).”

What the sources say

• Not checked yetcites Hofer, 1996 source

In the paper

“These studies support a “two hit” model in which ELS, such as maternal separation, confers vulnerability to symptoms of psychiatric illness, but with symptom onset only occurring after exposure to a subsequent stressor (Bayer et al., 1999; Maynard et al., 2001).”

What the sources say

• Not checked yetcites Bayer et al., 1999 source
• Not checked yetcites Maynard et al., 2001 source

In the paper

“other studies demonstrate enhanced mesolimbic dopamine function, as evidenced by increased nucleus accumbens dopamine release in response to stress (Brake et al., 2004) or amphetamine (Hall et al., 1999), as well as increased locomotion in response to cocaine (Brake et al., 2004).”

What the sources say

• Not checked yetcites Brake et al., 2004 source
• Not checked yetcites Hall et al., 1999 source

In the paper

“These changes suggest that high levels of maternal care enhance HPA axis regulation and allow more control of the endocrine stress cascade and better regulation of emotional behavior.”

In the paper

“Matthews and colleagues have demonstrated decreased sensitivity to the enhancing effects of amphetamine and increased sensitivity to the blunting effects of D2 antagonists on behaviors related to approach motivation (Matthews et al., 1996bMatthews and Robbins, 2003).”

What the sources say

• Not checked yetcites Matthews et al., 1996b
• Not checked yetcites Matthews and Robbins, 2003

In the paper

“reduced conditioning to predictive appetitive cues, while possibly reflecting decreased motivation, might also indicate impairments in associative learning (Matthews et al., 1996a, 1996b).”

What the sources say

• Not checked yetcites Matthews et al., 1996a
• Not checked yetcites Matthews et al., 1996b

In the paper

“maternal separation results in a greater peak and duration of glucocorticoid release in response to stress, decreased GR expression, increased CRF expression, and reduced benzodiazepine receptor binding (Sánchez et al., 2001).”

What the sources say

• Not checked yetcites Sánchez et al., 2001 source

In the paper

“Given that maternal separation deprives rat pups from opportunities for maternal care, this paradigm would be expected to result in changes opposite to that seen in rats exposed to high levels of maternal care, and this does appear to be the case (Ladd et al., 2000).”

What the sources say

• Not checked yetcites Ladd et al., 2000

In the paper

“Pups raised by dams who exhibit high levels of maternal care demonstrate increases in hippocampal synaptogenesis (Liu et al., 2000), increased glucocorticoid receptor (GR) mRNA, decreased hypothalamic CRF mRNA (Liu et al., 1997), and increased benzodiazepine receptor binding in brain regions regulating emotion (Caldji et al., 2000b).”

What the sources say

• Not checked yetcites Liu et al., 2000
• Not checked yetcites Liu et al., 1997 source
• Not checked yetcites Caldji et al., 2000b

In the paper

“One explanation for these divergent findings might be the existence of differences in the timing and duration of separation.”

What the sources say

• Not checked yetcites McCool and Chappell, 2009
• Not checked yetcites Panksepp, 1981 source

In the paper

“This paradigm also results in deficits in reversal learning (Amitai et al., 2014; Li et al., 2007), as well as in learning new strategies based on a previously unrelated cue (attentional set shifting) (Schrijver and Würbel, 2001).”

What the sources say

• Not checked yetcites Amitai et al., 2014 source
• Not checked yetcites Li et al., 2007
• Not checked yetcites Schrijver and Würbel, 2001

In the paper

“By depriving animals of the play experiences that normally guide cortical development, post-weaning social isolation is conceptualized as a rodent model of adolescent adversity with long-lasting effects on neurobiology and behavior (Fone and Porkess, 2008; Lukkes et al., 2009; Robbins, 2016).”

What the sources say

• Not checked yetcites Fone and Porkess, 2008
• Not checked yetcites Lukkes et al., 2009 source
• Not checked yetcites Robbins, 2016 source

In the paper

“While most studies demonstrate decreased activation of the striatal regions in tasks engaging motivational and reward responsiveness processes, this was not the case when the specific stressor investigated was variations in parental warmth.”

In the paper

“For example, despite enhanced approach motivation compared to socially housed controls, when a reward task requires fewer lever presses, socially isolated rats end up receiving less reward due to perseveration (Morgan and Einon, 1975).”

What the sources say

• Not checked yetcites Morgan and Einon, 1975

In the paper

“However, in one study, while activation in the ventral striatum and putamen was decreased during anticipation, activity was increased during the delivery phase, but only for positive verbal feedback as opposed to monetary reward (Boecker et al., 2014).”

What the sources say

• Not checked yetcites Boecker et al., 2014 source

In the paper

“In tasks measuring liking, social isolation generally results in increased sucrose preference (Brenes and Fornaguera, 2008, 2009; Colonnello et al., 2011; Hall et al., 1998a; Van den Berg et al., 2000), although there are some discrepant reports (McCool and Chappell, 2009; Pisu et al., 2011).”

What the sources say

• Not checked yetcites Brenes and Fornaguera, 2008, 2009
• Not checked yetcites Colonnello et al., 2011 source
• Not checked yetcites Hall et al., 1998a

In the paper

“While institutionally reared children had decreased ventral striatal response to positive emotional faces (Goff et al., 2013), adolescents with a history of physical and sexual abuse demonstrated increased reactivity to positively valenced social stimuli (Dennison et al., 2016), suggesting a potential difference in the effects of neglect vs abuse.”

What the sources say

• Not checked yetcites Goff et al., 2013 source
• Not checked yetcites Dennison et al., 2016 source

In the paper

“Both tasks have two phases, an anticipation phase, in which the subject is given information about the potential for reward, and a delivery phase, in which the reward is received. By measuring brain activity during the anticipation and delivery phases, a motivational component and a reward responsiveness component can be inferred, respectively (Knutson et al., 2000; Lutz and Widmer, 2014; Wang et”

What the sources say

• Not checked yetcites Knutson et al., 2000 source
• Not checked yetcites Lutz and Widmer, 2014
• Not checked yetcites Wang et al., 2016 source

In the paper

“A major difference between the human fMRI studies and the animal studies is that while the animal studies rely almost solely on behavioral measures to infer reward processes, behavioral measures (reaction times, performance) are reported much less frequently in the human literature.”

In the paper

“These two studies suggest that, depending on gender and developmental timing of stressor and testing, low maternal warmth may increase the brain’s sensitivity to anticipation of reward.”

In the paper

“there is some indication that female rats exposed to variable stressors in adolescence (restraint, social defeat) demonstrate subsequent deficits in sucrose consumption (Bourke and Neigh, 2011; Pohl et al., 2007) while male animals do not (Bourke and Neigh, 2011; Novick et al., 2013; Pohl et al., 2007; Toth et al., 2008).”

What the sources say

• Not checked yetcites Bourke and Neigh, 2011
• Not checked yetcites Pohl et al., 2007 source
• Not checked yetcites Novick et al., 2013 source

In the paper

“Increased indices of approach motivation are also found following social isolation, with evidence of enhanced responding for increasing concentrations of sucrose (Cuenya et al., 2015; Hall et al., 1997), as well as greater conditioned responses to sucrose-related stimuli (Jones et al., 1990).”

What the sources say

• Not checked yetcites Cuenya et al., 2015 source
• Not checked yetcites Hall et al., 1997 source
• Not checked yetcites Jones et al., 1990 source

In the paper

“As with maternal separation, post-weaning social isolation results in enhanced sensitivity of the HPA axis, especially in male rats (Holson et al., 1991; Viveros et al., 1988; Weiss et al., 2004), as well as an overall anxiogenic phenotype.”

What the sources say

• Not checked yetcites Holson et al., 1991 source
• Not checked yetcites Viveros et al., 1988
• Not checked yetcites Weiss et al., 2004 source

In the paper

“This relationship was significant when the stress was experienced earlier in life (kindergarten through grade 3) but not later (Hanson et al., 2016).”

What the sources say

• Not checked yetcites Hanson et al., 2016 source

In the paper

“A similar association was found for adolescent females with low maternal warmth in early adolescence, although increased activity was associated with increased depressive symptoms (Casement et al., 2014).”

What the sources say

• Not checked yetcites Casement et al., 2014 source

In the paper

“For example, women with a history of both childhood sexual abuse and MDD (Pechtel and Pizzagalli, 2013), adolescents exposed to physical abuse (Hanson et al., 2017), and young adults who had high levels of various adversities in early life (Birn et al., 2017) demonstrate decreased reinforcement learning.”

What the sources say

• Not checked yetcites Pechtel and Pizzagalli, 2013
• Not checked yetcites Hanson et al., 2017 source
• Not checked yetcites Birn et al., 2017 source

In the paper

“While changes to reward processing did not mediate the association between ELS and ADHD, similar patterns of ventral striatal activity were found (Boecker et al., 2014).”

What the sources say

• Not checked yetcites Boecker et al., 2014 source

In the paper

“As posited in the introduction, ELS likely alters core aspects of affect and cognition that in turns makes individuals susceptible to psychopathology.”

In the paper

“Dillon et al. (2009) and Boeker et al. (2014) found increased reaction times in individuals with prior ELS in the monetary incentive delay task, while decreased reaction times were noted in children with reactive attachment disorder in a gambling task (Takiguchi et al., 2015), although the remainder of studies either did not measure behavior (Casement et al., 2015, 2014; Goff et al., 2013; Hanson”

What the sources say

• Not checked yetcites Dillon et al., 2009 source
• Not checked yetcites Boecker et al., 2014 source
• Not checked yetcites Takiguchi et al., 2015 source

In the paper

“While it does appear that decreased striatal responsiveness in humans is linked to anhedonia and depressive symptoms, studies measuring how this impacts actual behavior are lacking.”

In the paper

“To our knowledge, interventions meant to target subclinical anhedonia or impairments in reinforcement learning in at risk populations have yet to be tested, however there is evidence for potential efficacy.”

What the sources say

• Not checked yetcites Mori et al., 2016 source
• Not checked yetcites Garland, 2016 source
• Not checked yetcites Acheson et al., 2013 source

In the paper

“in many of the human studies reviewed, decreased activation in regions of the basal ganglia to the anticipation or receipt of reward was not only associated with depressive symptoms (Dillon et al., 2009; Goff et al., 2013), but often found to mediate the relationship between ELS and depression (Corral-Frías et al., 2015; Hanson et al., 2015).”

What the sources say

• Not checked yetcites Dillon et al., 2009 source
• Not checked yetcites Goff et al., 2013 source
• Not checked yetcites Corral-Frías et al., 2015 source

In the paper

“The monetary incentive delay task and the reward guessing task, while well adapted for use with imaging, are less suited to capturing differences in reward behavior.”

In the paper

“It should be noted that in various studies utilizing fMRI and the monetary incentive delay task, changes in ventral striatal activation are often found in the absence of changes in reaction time (Jansma et al., 2013; Saji et al., 2013; Smoski et al., 2011), suggesting that reaction time may lack sensitivity as a marker for reward processing.”

What the sources say

• Not checked yetcites Jansma et al., 2013 source
• Not checked yetcites Saji et al., 2013 source
• Not checked yetcites Smoski et al., 2011 source

In the paper

“When individuals who have completed behavioral activation therapy are challenged with a monetary incentive delay task, they demonstrate increased activation of the ventromedial PFC during anticipation of a loss, which is interpreted as allowing for ongoing engagement in rewarding activity despite negative emotions (Mori et al., 2016).”

What the sources say

• Not checked yetcites Mori et al., 2016 source

In the paper

“Overall, a limited literature in humans does suggest that ELS is associated with decreased neural responsiveness to reward on both measures of approach motivation and reward responsiveness, although studies evaluating decreased maternal warmth appear to be an exception.”