Klaus B. Bærentsen

An activity theory approach to affordance

The concept of affordance was introduced to the field of HCI as a means to enhance the understandability and usability of artifacts and especially their user interface. The results have however not been entirely convincing. This paper presents a theoretical analysis of the concept of affordance coined by James J. Gibson. The concept of affordance was meant to cut through the subjective-objective dichotomy of traditional psychology and philosophy, but its interpretation in HCI has often retained this dichotomy. We argue, that at least some of the misunderstanding of the concept is caused by the fact that Gibson focused mainly on the perceptual side of the concept, leaving the activity of the organism as a largely implicit precondition. We suggest that this shortcoming have significant consequences, but that they can be overcome by employing the concepts for activity and consciousness found in the Russian activity theory as a frame of reference for the concept of affordance.

Music in minor activates limbic structures : a relationship with dissonance?

Using functional magnetic resonance imaging, we contrasted major and minor mode melodies controlled for liking to study the neural basis of musical mode perception. To examine the influence of the larger dissonance in minor melodies on neural activation differences, we further introduced a strongly dissonant stimulus, in the form of a chromatic scale. Minor mode melodies were evaluated as sadder than major melodies, and in comparison they caused increased activity in limbic structures, namely left parahippocampal gyrus, bilateral ventral anterior cingulate, and in left medial prefrontal cortex. Dissonance explained some, but not all, of the heightened activity in the limbic structures when listening to minor mode music.

Listen, Learn, Like! Dorsolateral Prefrontal Cortex Involved in the Mere Exposure Effect in Music

We used functional magnetic resonance imaging to investigate the neural basis of the mere exposure effect in music listening, which links previous exposure to liking. Prior to scanning, participants underwent a learning phase, where exposure to melodies was systematically varied. During scanning, participants rated liking for each melody and, later, their recognition of them. Participants showed learning effects, better recognising melodies heard more often. Melodies heard most often were most liked, consistent with the mere exposure effect. We found neural activations as a function of previous exposure in bilateral dorsolateral prefrontal and inferior parietal cortex, probably reflecting retrieval and working memory-related processes. This was despite the fact that the task during scanning was to judge liking, not recognition, thus suggesting that appreciation of music relies strongly on memory processes. Subjective liking per se caused differential activation in the left hemisphere, of the anterior insula, the caudate nucleus, and the putamen.

Patanjali and neuroscientific research on meditation

The definition of meditation (or yoga) by Patanjali as “restriction (or stilling) of the fluctuations of the mind” (cf, Woods, 1927/2003, p. xxx, 8) may be an appropriate starting point for research on meditation using fMRI. An operational definition of the neural substrate of meditation which is adequate to Patanjalis definition, may be developed on the basis of a non-reductionistic understanding of the neural underpinnings of the mind in terms of dynamical functional brain systems.

Visually induced gains in pitch discrimination: Linking audio-visual processing with auditory abilities

Perception is fundamentally a multisensory experience. The principle of inverse effectiveness (PoIE) states how the multisensory gain is maximal when responses to the unisensory constituents of the stimuli are weak. It is one of the basic principles underlying multisensory processing of spatiotemporally corresponding crossmodal stimuli that are well established at behavioral as well as neural levels. It is not yet clear, however, how modality-specific stimulus features influence discrimination of subtle changes in a crossmodally corresponding feature belonging to another modality. Here, we tested the hypothesis that reliance on visual cues to pitch discrimination follow the PoIE at the interindividual level (i.e., varies with varying levels of auditory-only pitch discrimination abilities). Using an oddball pitch discrimination task, we measured the effect of varying visually perceived vertical position in participants exhibiting a wide range of pitch discrimination abilities (i.e., musicians and nonmusicians). Visual cues significantly enhanced pitch discrimination as measured by the sensitivity index d’, and more so in the crossmodally congruent than incongruent condition. The magnitude of gain caused by compatible visual cues was associated with individual pitch discrimination thresholds, as predicted by the PoIE. This was not the case for the magnitude of the congruence effect, which was unrelated to individual pitch discrimination thresholds, indicating that the pitch-height association is robust to variations in auditory skills. Our findings shed light on individual differences in multisensory processing by suggesting that relevant multisensory information that crucially aids some perceivers’ performance may be of less importance to others, depending on their unisensory abilities.

Correction to: Visually induced gains in pitch discrimination: Linking audio-visual processing with auditory abilities

During copy-editing, the y-axes of Fig. 2 (top) and Fig. 3 (top) were erroneously labelled mean BCG (d’) in the version of the paper published as Online First. The correct label is meanCE (d’).