Brain Areas Consistently Linked to Individual Differences in Perceptual Decision-making in Younger as well as Older Adults before and after Training

Abstract

Abstract■ Perceptual decision-making performance depends on several cognitive and neural processes. Here, we fit Ratcliffʼs diffusion model to accuracy data and reaction-time distributions from one numerical and one verbal two-choice perceptual-decision task to deconstruct these performance measures into the rate of evidence accumulation (i.e., drift rate), response criterion setting (i.e., boundary separation), and peripheral aspects of performance (i.e., nondecision time). These theoretical processes are then related to individual differences in brain activation by means of multiple regression. The sample consisted of 24 younger and 15 older adults performing the task in fMRI before and after 100 daily 1-hr behavioral training sessions in a multitude of cognitive tasks. Results showed that individual differences in boundary separation were related to striatal activity, whereas differences in drift rate were related to activity in the inferior parietal lobe. These associations were not significantly modified by adult age or perceptual expertise. We conclude that the striatum is involved in regulating response thresholds, whereas the inferior parietal lobe might represent decision-making evidence related to letters and numbers. ■

Facilitation of Inferior Frontal Cortex by Transcranial Direct Current Stimulation Induces Perceptual Learning of Severely Degraded Speech

“…The results raise the possibility that facilitation of the IPC leads to an increased integration of the degraded acoustic word and the undegraded written word, resulting in a response bias toward identical pairs. On a more general level, our data support the putatively supramodal role of the IPC during discrimination tasks, where this area is a hub of a network involved in perceptual decision making (Kühn et al, 2011).…”

“…Depending on the experimental operationalization, the generalization of a previously established differential response to a new stimulus can be a mandatory feature for perceptual learning (Wohlwill, 1958;Goldstone, 1998;Loebach et al, 2009). In our study, participants were intensively trained on a same-different forced-choice paradigm to discriminate between MPs and IPs.…”

“…Adaptation profits from sentential semantics (Obleser et al, 2007) and phonological information supplied by nonwords (Hervais-Adelman et al, 2008), and even basic durational and spectral cues may support learning (Winn et al, 2012). Similarly, generalization to untrained material, a crucial trait of perceptual learning (Wohlwill, 1958), may apply to domains beyond speech, such as identification of environmental sounds (Loebach et al, 2009).…”

The dynamics of change in striatal activity following updating training

“…Studies on cortical brain activity report both increases [Hempel et al, 2004;Olesen et al, 2004;Westerberg and Klingberg, 2007] as well as decreases [Dahlin et al, 2008;Hempel et al, 2004;Kelly and Garavan, 2005;Kelly et al, 2006;Kü hn et al, 2011] of fronto-parietal activation during task performance after training. The basal ganglia are also involved in working memory [Cools et al, 2008;McNab and Klingberg, 2008].…”

Beyond extrastriate body area (EBA) and fusiform body area (FBA): context integration in the meaning of actions

“…Based on these findings, many authors have claimed that EBA/FBA should be directly involved in complex functions such as perceiving goal-directed actions and other higher-level related processes (Costantini et al, 2005; Saxe et al, 2006; Moro et al, 2008; Marsh et al, 2010; Kuhn et al, 2011). However, as suggested by Downing and Peelen (2011), it might be more accurate to interpret the activity of these regions in terms of populations of neurons that selectively encode and make explicit low-level visual features of human bodies like body shape and posture.…”