Is increased sensitivity to punishment a common characteristic of attention deficit/hyperactivity disorder? An experimental study of response allocation in Japanese children

Research on motivational processes in attention deficit/hyperactivity disorder (ADHD) focuses on reward. Studies with punishment are limited and findings mixed. This study evaluated the effects of punishment on response allocation in Japanese children with and without ADHD. Thirty-four children meeting DSM-IV criteria for ADHD and 59 typically developing control-group children completed an operant task in which they choose between playing two simultaneously available games. Reward was arranged symmetrically across the games under concurrent variable interval schedules. Asymmetric punishment schedules were superimposed with responses on one game punished four times as often as responses on the other. Children with ADHD showed greater behavioral sensitivity to punishment than controls. They allocated significantly more responses to the less frequently punished alternative and were more likely to play this game on consecutive trials and responded more slowly to the more punished game. Control group children allocated their responses evenly across games. Punishment exerted greater control over the behavior of Japanese children with ADHD than controls, similar to findings with children from Western countries, suggesting this is a common characteristic of the disorder. The behavior of typically developing Japanese children, while demonstrating awareness of punishment, was not controlled by the frequency of its occurrence

An Adaptation of Pavlovian-to-Instrumental Transfer (PIT) Methodology to Examine the Energizing Effects of Reward-Predicting Cues on Behavior in Young Adults

There is growing recognition that much of human behavior is governed by the presence of classically conditioned cues. The Pavlovian-to-Instrumental Transfer (PIT) paradigm offers a way to measure the effects of classically conditioned stimuli on behavior. In the current study, a novel behavioral task, an adaptation of the PIT framework, was developed for use in conjunction with an fMRI classical conditioning task. Twenty-four healthy young adults completed (1) instrumental training, (2) Pavlovian conditioning, and (3) a Transfer test. During instrumental training, participants learned to apply force to a handgrip to win money from slot machines pictured on a computer screen. During Pavlovian conditioning, slot machines appeared with one of two abstract symbols (cues), one symbol was predictive of monetary reward. During the Transfer test, participants again applied force to a handgrip to win money. This time, the slot machines were presented with the Pavlovian cues, but with the outcomes hidden. The results indicated increased effort on the instrumental task, i.e. higher response frequency and greater force, in the presence of the reward-predicting cue. Our findings add to the growing number of studies demonstrating PIT effects in humans. This new paradigm is effective in measuring the effects of a conditioned stimulus on behavioral activation

Altered functional brain connectivity in a non-clinical sample of young adults with attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) is characterized by symptoms of inattention and hyperactivity/impulsivity that often persist in adulthood. There is a growing consensus that ADHD is associated with abnormal function of diffuse brain networks, but such alterations remain poorly characterized. Using resting-state functional magnetic resonance imaging, we characterized multivariate (complex network measures), bivariate (network-based statistic), and univariate (regional homogeneity) properties of brain networks in a non-clinical, drug-naive sample of high-functioning young men and women with ADHD (nine males, seven females) and a group of matched healthy controls. Data from our sample allowed the isolation of intrinsic functional connectivity alterations specific to ADHD diagnosis and symptoms that are not related to developmental delays, general cognitive dysfunction, or history of medication use. Multivariate results suggested that frontal, temporal, and occipital cortices were abnormally connected locally as well as with the rest of the brain in individuals with ADHD. Results from the network-based statistic support and extend multivariate results by isolating two brain networks comprising regions between which inter-regional connectivity was significantly altered in the ADHD group; namely, a frontal amygdala-occipital network and a frontal temporal-occipital network. Brain behavior correlations further highlighted the key role of altered orbitofrontal-temporal and frontal-amygdala connectivity for symptoms of inattention and hyperactivity/impulsivity. All univariate properties were similar between groups. Taken together, results from this study show that the diagnosis and the two main symptom dimensions of ADHD are related to altered intrinsic connectivity in orbitofrontal-temporal-occipital and fronto-amygdala-occipital networks. Accordingly, our findings highlight the importance of extending the conceptualization of ADHD beyond segregated fronto-striatal alterations

Focusing Is Hard! Brain Responses to Reward in Attention Deficit Hyperactivity Disorder

Have there been times when you just couldn’t focus on homework or wait for your turn to speak? We all have these experiences! But for some children and adults, focusing, sitting, or waiting is extra hard, and that gets them into trouble all the time. They may have something called, attention deficit hyperactivity disorder (ADHD). But why is it harder for them to do these things? We thought that perhaps a part of their brains might work a little differently. So, we looked inside the brains of college students to see their brain activity. We found that, for the students who had ADHD, one brain area was not very active when they were waiting for good things. When the brain sends signals that “good things are coming soon!” this helps us wait or focus, even during boring tasks! For those with ADHD, these signals might be weaker, making it harder to wait and focus

Wishes of Children With ADHD

Understanding the desires and motivations of children with ADHD is important in helping them thrive. Their inner worlds, however, have not been well captured. The Three Wishes task provides minimal cues and structure to elicit their desires and hopes in an unbiased manner. The wishes of 299 school-aged children with ADHD (193 boys, aged 6–12) were elicited during a research diagnostic assessment. We developed a coding scheme to characterize different aspects of their wishes, including beneficiary, valence, and immediacy. Maslow’s hierarchy of needs, adapted to take account of the participants’ ages, was used to identify the motivations underlying the children’s wishes. As expected, many of the wishes reported were for immediate fulfillment, with many reflecting material desires. Affiliative wishes, highlighting the children’s desire for positive interpersonal relationships, were also common. There was some evidence for self-actualization/self-betterment goals and a small number of altruistic wishes. A word cloud presents the content of the children’s wishes grouped according to this hierarchy. This study highlights the diversity and typicality of the self-reported needs, desires and hopes of children with ADHD. It also serves as a timely reminder of the value of seeking such information directly from children themselves

Methylphenidate modifies reward cue responses in adults with ADHD: An fMRI study

Attention deficit hyperactivity disorder (ADHD) has been associated with neural hyposensitivity to reward-predicting cues. Methylphenidate is widely used in the management of the disorder\u27s symptoms, but its effects on reward sensitivity in ADHD are unknown. The current study used fMRI to measure striatal responses to reward-predicting cues in adults with ADHD on and off methylphenidate and a control group, during a classical conditioning task. Responses to cued reward were also explored. Larger differences in the ventral striatum activation to reward cues versus non-reward cues were observed when the ADHD participants were on methylphenidate compared to placebo. In response to cued-reward outcome, an exploratory analysis showed methylphenidate reduced the BOLD time-series correlation between the dorsal striatum and dorsal medial prefrontal cortex. Methylphenidate\u27s therapeutic effects may be mediated by altering reward processing in individuals with ADHD

Abnormal Striatal BOLD Responses to Reward Anticipation and Reward Delivery in ADHD

Altered reward processing has been proposed to contribute to the symptoms of attention deficit hyperactivity disorder (ADHD). The neurobiological mechanism underlying this alteration remains unclear. We hypothesize that the transfer of dopamine release from reward to reward-predicting cues, as normally observed in animal studies, may be deficient in ADHD. Functional magnetic resonance imaging (fMRI) was used to investigate striatal responses to reward-predicting cues and reward delivery in a classical conditioning paradigm. Data from 14 high-functioning and stimulant-naïve young adults with elevated lifetime symptoms of ADHD (8 males, 6 females) and 15 well-matched controls (8 males, 7 females) were included in the analyses. During reward anticipation, increased blood-oxygen-level-dependent (BOLD) responses in the right ventral and left dorsal striatum were observed in controls, but not in the ADHD group. The opposite pattern was observed in response to reward delivery; the ADHD group demonstrated significantly greater BOLD responses in the ventral striatum bilaterally and the left dorsal striatum relative to controls. In the ADHD group, the number of current hyperactivity/impulsivity symptoms was inversely related to ventral striatal responses during reward anticipation and positively associated with responses to reward. The BOLD response patterns observed in the striatum are consistent with impaired predictive dopamine signaling in ADHD, which may explain altered reward-contingent behaviors and symptoms of ADHD

Minimally Invasive Surgery for Giant Oesophageal and Gastric Leiomyomas

Herein, we describe a case of a 41-year-old woman with two giant leiomyomas located in the lower thoracic oesophagus and gastric cardia that were treated by minimally invasive thoracoscopic and laparoscopic surgery. We first resected the gastric cardia and laparoscopically prepared a gastric tube, and then we resected the lower thoracic oesophagus and intrathoracically anastomosed the oesophagus and gastric tube using thoracoscopic surgery with the patient in the prone position. Two concurrent giant leiomyomas of the oesophagus and stomach are rare, and the choice of surgical procedure to address the tumour from the mediastinum into the abdominal cavity was particularly challenging. We selected a minimally invasive thoracoscopic approach with the patient in the prone position. This strategy seems effective for resecting these giant tumours in the lower thoracic oesophagus and gastric cardia

Development of a Classical Conditioning Task for Humans Examining Phasic Heart Rate Responses to Signaled Appetitive Stimuli: A Pilot Study

Cardiac responses to appetitive stimuli have been studied as indices of motivational states and attentional processes, the former being associated with cardiac acceleration and latter deceleration. Very few studies have examined heart rate changes in appetitive classical conditioning in humans. The current study describes the development and pilot testing of a classical conditioning task to assess cardiac responses to appetitive stimuli and cues that reliably precede them. Data from 18 adults were examined. They were shown initially neutral visual stimuli (putative CS) on a computer screen followed by pictures of high-caloric food (US). Phasic cardiac deceleration to food images was observed, consistent with an orienting response to motivationally significant stimuli. Similar responses were observed to non-appetitive stimuli when they were preceded by the cue associated with the food images, suggesting that attentional processes were engaged by conditioned stimuli. These autonomic changes provide significant information about classical conditioning effects in humans