Longitudinal changes in behavioral approach system sensitivity and brain structures involved in reward processing during adolescence

[Correction Notice: An Erratum for this article was reported in Vol 48(5) of Developmental Psychology (see record 2012-09244-001). Figure 2 was distorted in production. The correct version is presented in the erratum.] Adolescence is a period of radical normative changes and increased risk for substance use, mood disorders, and physical injury. Researchers have proposed that increases in reward sensitivity (i.e., sensitivity of the behavioral approach system [BAS]) and/or increases in reactivity to all emotional stimuli (i.e., reward and threat sensitivities) lead to these phenomena. The present study is the first longitudinal investigation of changes in reward (i.e., BAS) sensitivity in 9- to 23-year-olds across a 2-year follow-up. Support was found for increased reward sensitivity from early to late adolescence, and evidence was found for decline in the early 20s. This decline is combined with a decrease in left nucleus accumbens (Nacc) volume, a key structure for reward processing, from the late teens into the early 20s. Furthermore, we found longitudinal increases in sensitivity to reward to be predicted by individual differences in the Nacc and medial orbitofrontal cortex (OFC) volumes at baseline in this developmental sample. Similarly, increases in sensitivity to threat (i.e., behavioral inhibition system sensitivity) were qualified by sex, with only females participants experiencing this increase, and predicted by individual differences in lateral OFC volumes at baseline. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Molecular reduction: reality or fiction?

Neurophysiological research suggests our mental life is related to the cellular processes of particular nerves. In the spirit of Occam’s razor, some authors take these connections as reductions of psychological terms and kinds to molecular- biological mechanisms and patterns. Bickle’s ‘intervene cellularly/molecularly and track behaviourally’ reduction is one example of this. Here the mental is being reduced to the physical in two steps. The first is, through genetically altered mammals, to causally alter activity of particular nerve cells, i.e. neurons, at the molecular level and then, under controlled experimental conditions, to use generally-accepted rules of behaviour within psychology to monitor the results of these manipulations. In this article, we argue that Bickle’s case example for molecular reduction, i.e. the reduction of long-term memory to its cellular-molecular mechanisms, cannot support his claims, because it turns out that his chosen molecular pathway is neither a sufficient nor a necessary condition for the memory consolidation switch, and thus, instead of rejecting the multiple realization argument, Bickle’s argument actually speaks in favour of it. Therefore the idea of reductive connections between our mental life and the activity of particular nerves is, at present, still more fiction than reality.     

Reversal negativity and bistable stimuli: Attention,awareness, or something else?

Ambiguous (or bistable) figures are visual stimuli that have two mutually exclusive perceptual interpretations that spontaneously alternate with each other. Perceptual reversals, as compared with non-reversals, typically elicit a negative difference called reversal negativity (RN), peaking around 250 ms from stimulus onset. The cognitive interpretation of RN remains unclear: it may reflect either bottom-up processes, attentional processes that select between the alternative views of the stimulus, or it may reflect the change in the contents of subjective awareness. In the present study, event-related potentials in response to endogenous unilateral and bilateral reversals of two Necker lattices were compared with exogenously induced reversals of unambiguous lattices. The RN neither resembled the attention-related N2pc response, nor did it correlate with the content of subjective visual awareness. Thus, we conclude that RN is a non-attentional ERP correlate of the changes in the perceptual configuration of the presented object.     

Beyond Single-Mindedness: A Figure-Ground Reversal for the Cognitive Sciences

A fundamental fact about human minds is that they are never truly alone: all minds are steeped in situated interaction. That social interaction matters is recognized by any experimentalist who seeks to exclude its influence by studying individuals in isolation. On this view, interaction complicates cognition. Here, we explore the more radical stance that interaction co-constitutes cognition: that we benefit from looking beyond single minds toward cognition as a process involving interacting minds. All around the cognitive sciences, there are approaches that put interaction center stage. Their diverse and pluralistic origins may obscure the fact that collectively, they harbor insights and methods that can respecify foundational assumptions and fuel novel interdisciplinary work. What might the cognitive sciences gain from stronger interactional foundations? This represents, we believe, one of the key questions for the future. Writing as a transdisciplinary collective assembled from across the classic cognitive science hexagon and beyond, we highlight the opportunity for a figure-ground reversal that puts interaction at the heart of cognition. The interactive stance is a way of seeing that deserves to be a key part of the conceptual toolkit of cognitive scientists.