Förderzeitraum 2016
Refine
Has Fulltext
- yes (4)
Is part of the Bibliography
- yes (4)
Year of publication
- 2016 (4)
Document Type
- Journal article (4)
Language
- English (4)
Keywords
- Broca (1)
- Motivation (1)
- P300 speller (1)
- Personality (1)
- aphasia (1)
- behavior (1)
- brain-computer interface (BCI) (1)
- decision making (1)
- electroencephalography (1)
- emotions (1)
Institute
- Institut für Psychologie (4) (remove)
People with post-stroke motor aphasia know what they would like to say but cannot express it through motor pathways due to disruption of cortical circuits. We present a theoretical background for our hypothesized connection between attention and aphasia rehabilitation and suggest why in this context, Brain-Computer Interface (BCI) use might be beneficial for patients diagnosed with aphasia. Not only could BCI technology provide a communication tool, it might support neuronal plasticity by activating language circuits and thereby boost aphasia recovery. However, stroke may lead to heterogeneous symptoms that might hinder BCI use, which is why the feasibility of this approach needs to be investigated first. In this pilot study, we included five participants diagnosed with post-stroke aphasia. Four participants were initially unable to use the visual P300 speller paradigm. By adjusting the paradigm to their needs, participants could successfully learn to use the speller for communication with accuracies up to 100%. We describe necessary adjustments to the paradigm and present future steps to investigate further this approach.
Out of the corner of the driver's eye: Peripheral processing of hazards in static traffic scenes
(2016)
Effective gaze control in traffic, based on peripheral visual information, is important to avoid hazards. Whereas previous hazard perception research mainly focused on skill-component development (e.g., orientation and hazard processing), little is known about the role and dynamics of peripheral vision in hazard perception. We analyzed eye movement data from a study in which participants scanned static traffic scenes including medium-level versus dangerous hazards and focused on characteristics of fixations prior to entering the hazard region. We found that initial saccade amplitudes into the hazard region were substantially longer for dangerous (vs. medium-level) hazards, irrespective of participants' driving expertise. An analysis of the temporal dynamics of this hazard-level dependent saccade targeting distance effect revealed that peripheral hazard-level processing occurred around 200–400 ms during the course of the fixation prior to entering the hazard region. An additional psychophysical hazard detection experiment, in which hazard eccentricity was manipulated, revealed better detection for dangerous (vs. medium-level) hazards in both central and peripheral vision. Furthermore, we observed a significant perceptual decline from center to periphery for medium (but not for highly) dangerous hazards. Overall, the results suggest that hazard processing is remarkably effective in peripheral vision and utilized to guide the eyes toward potential hazards.
The present study investigates how different emotions can alter social bargaining behavior. An important paradigm to study social bargaining is the Ultimatum Game. There, a proposer gets a pot of money and has to offer part of it to a responder. If the responder accepts, both players get the money as proposed by the proposer. If he rejects, none of the players gets anything. Rational choice models would predict that responders accept all offers above 0. However, evidence shows that responders typically reject a large proportion of all unfair offers. We analyzed participants’ behavior when they played the Ultimatum Game as responders and simultaneously collected electroencephalogram data in order to quantify the feedback-related negativity and P3b components. We induced state affect (momentarily emotions unrelated to the task) via short movie clips and measured trait affect (longer-lasting emotional dispositions) via questionnaires. State happiness led to increased acceptance rates of very unfair offers. Regarding neurophysiology, we found that unfair offers elicited larger feedback-related negativity amplitudes than fair offers. Additionally, an interaction of state and trait affect occurred: high trait negative affect (subsuming a variety of aversive mood states) led to increased feedback-related negativity amplitudes when participants were in an angry mood, but not if they currently experienced fear or happiness. We discuss that increased rumination might be responsible for this result, which might not occur, however, when people experience happiness or fear. Apart from that, we found that fair offers elicited larger P3b components than unfair offers, which might reflect increased pleasure in response to fair offers. Moreover, high trait negative affect was associated with decreased P3b amplitudes, potentially reflecting decreased motivation to engage in activities. We discuss implications of our results in the light of theories and research on depression and anxiety.
Theta oscillations in the EEG have been shown to reflect ongoing cognitive processes related to mental effort. Here, we show that the pattern of theta oscillation in response to varying cognitive demands reflects stable individual differences in the personality trait epistemic motivation: Individuals with high levels of epistemic motivation recruit relatively more cognitive resources in response to situations possessing high, compared to low, cognitive demand; individuals with low levels do not show such a specific response. Our results provide direct evidence for the theory of the construct need for cognition and add to our understanding of the neural processes underlying theta oscillations. More generally, we provide an explanation how individual differences in personality traits might be represented on a neural level.