Seeing and thinking: Foundational issues and empirical horizons

Subjective and objective assessments of executive functions are independently predictive of aggressive tendencies in patients with substance use disorder

BACKGROUND AND AIMS

Impairments in executive functions have been found to influence violent behavior. Executive functions are crucial in the treatment of patients with substance use disorders because substance use generally impairs cognitive processes and is therefore detrimental for executive functions thereby reducing control of behavior and thus of consumption impulses. We studied correlations between subjective, i.e. self-report, and objective, i.e. behavior-based, assessment of executive functions and the predictive validity of these measures for aggression in patients with substance use disorder.

METHODS

The study included 64 patients with a diagnosed substance use disorder who were convicted according to the German Criminal Code for crimes they committed in the context of their disorder and were therefore in treatment in forensic psychiatric departments in Germany. Multiple self-report and behavior-based instruments were used to assess executive functions, appetitive and facilitative aggression as well as clinical and sociodemographic variables.

RESULTS

Participants showed impaired executive functions, and measures of executive functions predicted aggressive tendencies and violent offenses. Despite ecological validity of the findings, the subjective and objective assessments of executive functions did not correlate with each other, which corroborates studies in other clinical settings.

CONCLUSIONS

We discuss that this finding may be due to the conceptual differences between subjective and objective measures. Therefore, self-report and behavior-based measures should not be used as proxies of each other but as complementary measures that are useful for comprehensive diagnostics of cognitive impairments and assessment of risks for violent behavior.

Minding the gut: extending embodied cognition and perception to the gut complex

Scientific and philosophical accounts of cognition and perception have traditionally focused on the brain and external sense organs. The extended view of embodied cognition suggests including other parts of the body in these processes. However, one organ has often been overlooked: the gut. Frequently conceptualized as merely a tube for digesting food, there is much more to the gut than meets the eye. Having its own enteric nervous system, sometimes referred to as the "second brain," the gut is also an immune organ and has a large surface area interacting with gut microbiota. The gut has been shown to play an important role in many physiological processes, and may arguably do so as well in perception and cognition. We argue that proposals of embodied perception and cognition should take into account the role of the "gut complex," which considers the enteric nervous, endocrine, immune, and microbiota systems as well as gut tissue and mucosal structures. The gut complex is an interface between bodily tissues and the "internalized external environment" of the gut lumen, involved in many aspects of organismic activity beyond food intake. We thus extend current embodiment theories and suggest a more inclusive account of how to "mind the gut" in studying cognitive processes.

The No-Report Paradigm: A Revolution in Consciousness Research?

In the cognitive neuroscience of consciousness, participants have commonly been instructed to report their conscious content. This, it was claimed, risks confounding the neural correlates of consciousness (NCC) with their preconditions, i.e., allocation of attention, and consequences, i.e., metacognitive reflection. Recently, the field has therefore been shifting towards no-report paradigms. No-report paradigms draw their validity from a direct comparison with no-report conditions. We analyze several examples of such comparisons and identify alternative interpretations of their results and/or methodological issues in all cases. These go beyond the previous criticism that just removing the report is insufficient, because it does not prevent metacognitive reflection. The conscious mind is fickle. Without having much to do, it will turn inward and switch, or timeshare, between the stimuli on display and daydreaming or mind-wandering. Thus, rather than the NCC, no-report paradigms might be addressing the neural correlates of conscious disengagement. This observation reaffirms the conclusion that no-report paradigms are no less problematic than report paradigms.

In absence of an explicit judgment, action-specific effects still influence an action measure of perceived speed

Action-specific effects, such as a fish appearing faster when it is harder to catch, have been primarily demonstrated using explicit perceptual judgments. These sorts of judgments rely on the cognitive or "what" visual pathway. An open question is whether action-specific effects also influence the action pathway. If fish look faster when the net is small, the net should be released earlier than when the net is big. Previously, this action measure was always paired with an explicit measure of fish speed, which is known to evoke the cognitive visual pathway. Here, net release time was examined without any explicit judgments. The action-specific effect of net size still emerged. Assuming net release time taps into the action pathway, the current studies provide support that action-specific effects occur within both the cognitive and action pathways, possibly because these effects operate on early visual processes prior to the split between the two pathways.

Is There a Chastity Belt on Perception?

Can one's ability to perform an action, such as hitting a softball, influence one's perception? According to the action-specific account, perception of spatial layout is influenced by the perceiver's abilities to perform an intended action. Alternative accounts posit that purported effects are instead due to nonperceptual processes, such as response bias. Despite much confirmatory research on both sides of the debate, researchers who promote a response-bias account have never used the Pong task, which has yielded one of the most robust action-specific effects. Conversely, researchers who promote a perceptual account have rarely used the opposition's preferred test for response bias, namely, the postexperiment survey. The current experiments rectified this. We found that even for people naive to the experiment's hypothesis, the ability to block a moving ball affected the ball's perceived speed. Moreover, when participants were explicitly told the hypothesis and instructed to resist the influence of their ability to block the ball, their ability still affected their perception of the ball's speed.

Pre-cueing, the Epistemic Role of Early Vision, and the Cognitive Impenetrability of Early Vision

I have argued (Raftopoulos, 2009, 2014) that early vision is not directly affected by cognition since its processes do not draw on cognition as an informational resource; early vision processes do not operate over cognitive contents, which is the essence of the claim that perception is cognitively penetrated; early vision is cognitively impenetrable. Recently it has been argued that there are cognitive effects that affect early vision, such as the various pre-cueing effects guided by cognitively driven attention, which suggests that early vision is cognitively penetrated. In addition, since the signatures of these effects are found in early vision it seems that early vision is directly affected by cognition since its processes seem to use cognitive information. I defend the cognitive impenetrability of early vision in three steps. First, I discuss the problems the cognitively penetrability of perception causes for the epistemic role of perception in grounding perceptual beliefs. Second, I argue that whether a set of perceptual processes is cognitively penetrated hinges on whether there are cognitive effects that undermine the justificatory role of these processes in grounding empirical beliefs, and I examine the epistemic role of early vision. I argue, third, that the cognitive effects that act through pre-cueing do not undermine this role and, thus, do not render early vision cognitively penetrable. In addition, they do not entail that early vision uses cognitive information.

Cognitive Penetration and Attention

Zenon Pylyshyn argues that cognitively driven attentional effects do not amount to cognitive penetration of early vision because such effects occur either before or after early vision. Critics object that in fact such effects occur at all levels of perceptual processing. We argue that Pylyshyn’s claim is correct—but not for the reason he emphasizes. Even if his critics are correct that attentional effects are not external to early vision, these effects do not satisfy Pylyshyn’s requirements that the effects be direct and exhibit semantic coherence. In addition, we distinguish our defense from those found in recent work by Raftopoulos and by Firestone and Scholl, argue that attention should not be assimilated to expectation, and discuss alternative characterizations of cognitive penetrability, advocating a kind of pluralism.

Action potential influences spatial perception: Evidence for genuine top-down effects on perception

The action-specific account of spatial perception asserts that a perceiver's ability to perform an action, such as hitting a softball or walking up a hill, impacts the visual perception of the target object. Although much evidence is consistent with this claim, the evidence has been challenged as to whether perception is truly impacted, as opposed to the responses themselves. These challenges have recently been organized as six pitfalls that provide a framework with which to evaluate the empirical evidence. Four case studies of action-specific effects are offered as evidence that meets the framework's high bar, and thus that demonstrates genuine perceptual effects. That action influences spatial perception is evidence that perceptual and action-related processes are intricately and bidirectionally linked.