Braem, S., De Houwer, J., Demanet, J, Yuen, K. S. L., Kalisch, R., & Brass, M. (2017). Pattern analyses reveal separate experience-based fear memories in the human right amygdala. Journal of Neuroscience, 37, 8116–8130.
Learning fear via the experience of contingencies between a conditioned stimulus (CS) and an
aversive unconditioned stimulus (US) is often assumed to be fundamentally different from
learning fear via instructions. An open question is whether fear-related brain areas respond
differently to experienced CS-US contingencies than to merely instructed CS-US contingencies.
Here, we contrasted two experimental conditions where subjects were instructed to expect the
same CS-US contingencies while only one condition was characterized by prior experience with
the CS-US contingency. Using multi-voxel pattern analysis of fMRI data, we found CS-related
neural activation patterns in the right amygdala (but not in other fear-related regions) that
dissociated between whether a CS-US contingency had been instructed and experienced versus
merely instructed. A second experiment further corroborated this finding by showing a
category-independent neural response to instructed and experienced, but not merely instructed,
CS presentations in the human right amygdala. Together, these findings are in line with
previous studies showing that verbal fear instructions have a strong impact on both brain and
behaviour. However, even in the face of fear instructions, the human right amygdala still shows
a separable neural pattern response to experience-based fear contingencies.
Braem, S., Liefooghe, B., De Houwer, J., Brass, M., & Abrahamse, E. (2017). There are limits to the effects of task instructions: Making the automatic effects of task instructions context-specific takes practice. Journal of Experimental Psychology: Learning, Memory, & Cognition, 43, 394-403.
Unlike other animals, humans have the unique ability to share and use verbal instructions to prepare
for upcoming tasks. Recent research showed that instructions are sufficient for the automatic, reflexlike activation of responses. However, systematic studies into the limits of these automatic effects of
task instructions remain relatively scarce. In this study, we set out to investigate whether this
instruction-based automatic activation of responses can be context-dependent. Specifically,
participants performed a task of which the stimulus-response rules and context (location on the screen)
could either coincide or not with those of an instructed to-be-performed task (whose instructions
changed every run). In two experiments, we showed that the instructed task rules had an automatic
impact on performance – performance was slowed down when the merely instructed task rules did not
coincide, but, importantly, this effect was not context-dependent. Interestingly, a third and fourth
experiment suggests that context dependency can actually be observed, but only when practicing the
task in its appropriate context for over sixty trials or after a sufficient amount of practice on a fixed
context (the context was the same for all instructed tasks). Together, these findings seem to suggest
that instructions can establish stimulus-response representations that have a reflexive impact on
behavior, but are insensitive to the context in which the task is known to be valid. Instead, contextspecific task representations seem to require practice.
The ability to follow new instructions is crucial for acquiring behaviors and the cultural
transmission of performance-related knowledge. In this article, we discuss the observation
that successful instruction following seems to require both the capacity to understand verbal
information, but also the ability to transform this information into a procedural format. Here
we review the behavioural and neuroimaging literature on following new instructions and
discuss how it contributes to our understanding of the functional mechanisms underlying
instruction following. Based on this review, we distinguish three phases of instruction
following. In the instruction phase, the declarative information of the task instruction is
transformed into a task model consisting of a structured representation of the relevant
condition-action rules. In the implementation phase, elements of this task model are
transformed into a highly accessible state guiding behaviour. In the application phase, the
relevant condition-action rules are applied. We discuss the boundary conditions and capacity
limits of these phases, determine their neural correlates, and relate them to recent models
of working memory.
Mertens, G., Raes, A. K., & De Houwer, J. (In press). Can prepared fear conditioning result from verbal instructions? Learning and Motivation.
Evolutionary fear-relevant stimuli such as snakes or spiders are thought to be prepared to elicit fear reactions. This implies that the acquisition of conditioned fear responses is facilitated when these stimuli serve as conditioned stimuli (CSs). Moreover, extinction of conditioned fear responses is delayed when CSs are prepared stimuli. The research presented in this article addresses the question whether such selective learning effects can be obtained even when participants do not experience pairings of CSs and US but receive only instructions about those pairings. Two experiments were conducted in which participants were verbally informed about the relationship between fear-relevant and fear-irrelevant CSs and the presence of an electrical stimulus (US). However, CSs were never actually paired with the US. US expectancy ratings and skin conductance responses were recorded during multiple CS only trials. In the first experiment, we observed acquisition, extinction and reinstatement of fear on the basis of instructions, but these effects were not modulated by the fear-relevance of the CSs. In the second experiment, we manipulated whether participants actually experienced the CS-US contingencies or were merely instructed. We obtained facilitated acquisition for the merely instructed fear-relevant CS+. We discuss these results in relation to the evolutionary fear learning model of Öhman and Mineka (2001) and the expectancy bias model of Davey (1992).
Chambon*, V., Sidarus*, N., & Haggard, P. (2014). From action intentions to action effects: how does the sense of agency come about? Frontiers in Human Neuroscience, 8, 320. doi:10.3389/fnhum.2014.00320
Sense of agency refers to the feeling of controlling an external event through one’s own
action. On one influential view, agency depends on how predictable the consequences
of one’s action are, getting stronger as the match between predicted and actual effect
of an action gets closer. Thus, sense of agency arises when external events that follow
our action are consistent with predictions of action effects made by the motor system
while we perform or simply intend to perform an action. According to this view, agency
is inferred retrospectively, after an action has been performed and its consequences are
known. In contrast, little is known about whether and how internal processes involved
in the selection of actions may influence subjective sense of control, in advance of the
action itself, and irrespective of effect predictability. In this article, we review several
classes of behavioral and neuroimaging data suggesting that earlier processes, linked to
fluency of action selection, prospectively contribute to sense of agency. These findings
have important implications for better understanding human volition and abnormalities of
Caspar, E. Christensen, J.F., Cleeremans, A., & Haggard, P. (2016). Coercion changes the sense of agency in the human brain. Current Biology, 26, 1-8.
People may deny responsibility for negative conse- quences of their actions by claiming that they were ‘‘only obeying orders.’’ The ‘‘Nuremberg defense’’ of- fers one extreme example, though it is often dis- missed as merely an attempt to avoid responsibility. Milgram’s classic laboratory studies reported wide- spread obedience to an instruction to harm, suggest- ing that social coercion may alter mechanisms of voluntary agency, and hence abolish the normal experience of being in control of one’s own actions. However, Milgram’s and other studies relied on dissembling and on explicit measures of agency, which are known to be biased by social norms. Here, we combined coercive instructions to admin- ister harm to a co-participant, with implicit measures of sense of agency, based on perceived compres- sion of time intervals between voluntary actions and their outcomes, and with electrophysiological recordings. In two experiments, an experimenter ordered a volunteer to make a key-press action that caused either financial penalty or demonstrably painful electric shock to their co-participant, thereby increasing their own financial gain. Coercion increased the perceived interval between action and outcome, relative to a situation where partici- pants freely chose to inflict the same harms. Interest- ingly, coercion also reduced the neural processing of the outcomes of one’s own action. Thus, people who obey orders may subjectively experience their ac- tions as closer to passive movements than fully voluntary actions. Our results highlight the complex relation between the brain mechanisms that generate the subjective experience of voluntary ac- tions and social constructs, such as responsibility.
Borragan, G., Slama, H., Destrebecqz, A., & Peigneux, P. (2016). Cognitive Fatigue Facilitates Procedural Sequence Learning. Front Hum Neurosci, 10, 86. doi: 10.3389/fnhum.2016.00086
Enhanced procedural learning has been evidenced in conditions where cognitive control is diminished, including hypnosis, disruption of prefrontal activity and non-optimal time of the day. Another condition depleting the availability of controlled resources is cognitive fatigue (CF). We tested the hypothesis that CF, eventually leading to diminished cognitive control, facilitates procedural sequence learning. In a two-day experiment, 23 young healthy adults were administered a serial reaction time task (SRTT) following the induction of high or low levels of CF, in a counterbalanced order. CF was induced using the Time load Dual-back (TloadDback) paradigm, a dual working memory task that allows tailoring cognitive load levels to the individual's optimal performance capacity. In line with our hypothesis, reaction times (RT) in the SRTT were faster in the high- than in the low-level fatigue condition, and performance improvement was higher for the sequential than the motor components. Altogether, our results suggest a paradoxical, facilitating impact of CF on procedural motor sequence learning. We propose that facilitated learning in the high-level fatigue condition stems from a reduction in the cognitive resources devoted to cognitive control processes that normally oppose automatic procedural acquisition mechanisms.
Cleeremans, A. (in press). Connecting conscious and unconscious processing. Cognitive Science.
Consciousness remains a mystery — “a phenomenon that people don’t know how to think about —yet” (Dennett, 1991, p. 21). Here, I consider how the connectionist perspective on information processing may help us progress towards the goal of understanding the computational principles through which conscious and unconscious processing differ. I begin by delineating the conceptual challenges associated with classical approaches to cognition insofar as understanding unconscious information processing is concerned, and to highlight several contrasting computational principles that are constitutive of the connectionist approach. This leads me to suggest that conscious and unconscious processing are fundamentally connected, that is, rooted in the very same computational principles. I further develop a perspective according to which the brain continuously and unconsciously learns to redescribe its own activity itself based on on constant interaction with itself, with the world, and with other minds. The outcome of such interactions is the emergence of internal models that are metacognitive in nature and that function so as it make it possible for an agent to develop a (limited, implicit, practical) understanding of itself. In this light, plasticity and learning are constitutive of what makes us conscious, for it is in virtue of our own experiences with ourselves and with other people that our mental life acquires its subjective character. The connectionist framework continues to be uniquely positioned in the Cognitive Sciences to address the challenge of identifying what one could call the “computational correlates of consciousness” (Mathis & Mozer, 1996) because it makes it possible to focus on the mechanisms through which information processing takes place.
Schmidt, J. R., & De Houwer, J. (in press). Contingency learning tracks with stimulus-response proportion: No evidence of misprediction costs. Experimental Psychology.
We investigate the processes involved in human contingency learning using the colour-word contingency learning paradigm. In this task, participants respond to the print colour of neutral words. Each word is most often presented in one colour. Results show that participants respond faster and more accurately to words presented in their expected colour. In Experiment 1, we observed better performance for high relative to medium frequency word-colour pairs, and for medium relative to low frequency pairs. Within the medium frequency condition, it did not matter whether the word was predictive of a currently-unpresented colour, or the colour of a currently-unpresented word. We conclude that a given word facilitates each potential response proportional to how often they co-occurred. In contrast, there was no evidence for costs associated with violations of high-frequency expectancies. Experiment 2 further introduced a novel word baseline condition but also did not provide evidence for competition between retrieved responses.