No abstract

No abstract

Binding processes play a critical role in memory. We investigated whether the binding of (visually presented) verbal and spatial (locations) information involves general attentional resources, as stipulated in the revised working memory model, by comparing measures of binding in the presence and absence of a concurrent memory load. Using an adaptation of a probe recognition task contrasting performance between intact and recombined conditions, we found that the concurrent retention of a sequence of three pure tones eliminated verbal-spatial binding. The present study constitutes the first to directly measure the impact of a concurrent memory load on verbal-spatial binding and suggests that such binding may indeed recruit attentional resources, consistent with some recent findings in the visual-spatial binding literature.

Many cognitive abilities involve the integration of information from different modalities, a process referred to as "binding." It remains less clear, however, whether the creation of bound representations occurs in an involuntary manner, and whether the links between the constituent features of an object are symmetrical. We used magnetoencephalography to investigate whether oscillatory brain activity related to binding processes would be observed in conditions in which participants maintain one feature only (involuntary binding); and whether this activity varies as a function of the feature attended to by participants (binding asymmetry). Participants performed two probe recognition tasks that were identical in terms of their perceptual characteristics and only differed with respect to the instructions given (to memorize either consonants or locations). MEG data were reconstructed using a current source distribution estimation in the classical frequency bands. We observed implicit verbal-spatial binding only when participants successfully maintained the identity of consonants, which was associated with a selective increase in oscillatory activity over prefrontal regions in all frequency bands during the first half of the retention period and accompanied by increased activity in posterior brain regions. The increase in oscillatory activity in prefrontal areas was only observed during the verbal task, which suggests that this activity might be signaling neural processes specifically involved in cross-code binding. Current results are in agreement with proposals suggesting that the prefrontal cortex function as a "pointer" which indexes the features that belong together within an object.

Past research has demonstrated that the occurrence of unexpected task-irrelevant changes in the auditory or visual sensory channels captured attention in an obligatory fashion, hindering behavioral performance in ongoing auditory or visual categorization tasks and generating orientation and re-orientation electrophysiological responses. We report the first experiment extending the behavioral study of cross-modal distraction to tactile novelty. Using a vibrotactile-visual cross-modal oddball task and a bespoke hand-arm vibration device, we found that participants were significantly slower at categorizing the parity of visually presented digits following a rare and unexpected change in vibrotactile stimulation (novelty distraction), and that this effect extended to the subsequent trial (postnovelty distraction). These results are in line with past research on auditory and visual novelty and fit the proposition of common and amodal cognitive mechanisms for the involuntary detection of change.

Verbal–spatial bindings are integral to routine cognitive operations (e.g., reading), yet the processes supporting them in working memory are little understood. Campo and colleagues [Campo, P., Poch, C., Parmentier, F. B. R., Moratti, S., Elsley, J. V., Castellanos, N., … Maestú, F. (2010). Oscillatory activity in prefrontal and posterior regions during implicit letter-location binding. Neuroimage, 49, 2807–2815] recently reported data suggesting obligatory letter–location binding when participants were directed to remember the letters in a display (of letters in locations), but no evidence for binding when instructed to remember the filled locations. The present study contrasted two explanations for this binding asymmetry. First, it may result from an obligatory dependence on “where” during the representation of “what” information, while “where” information may be held independently of its contents (the strong asymmetry hypothesis). Second, it may constitute a snapshot of a dynamic feature inhibition process that had partially completed by test: the asymmetrical inhibition hypothesis. Using Campo and colleagues’ task with a variable retention interval between display and test, we presented four consonants in distinct locations and contrasted performance between “remember letters” and “remember locations” instructions. Our data supported the strong asymmetry hypothesis through demonstrating binding in the verbal task, but not in the spatial task. Critically, when present, verbal–spatial bindings were remarkably stable, enduring for at least 15 seconds.

The present study reports normative ratings for 200 food and non-food odors. One hundred participants rated odors across measures of verbalisability, perceived descriptive ability, context availability, pleasantness, irritability, intensity, familiarity, frequency, age of acquisition, and complexity. Analysis of the agreement between raters revealed that four dimensions, those of familiarity, intensity, pleasantness, and irritability, have the strongest utility as normative data. The ratings for the remaining dimensions exhibited reduced discriminability across the odor set and should therefore be used with caution. Indeed, these dimensions showed a larger difference between individuals in the ratings of the odors. Familiarity was shown to be related to pleasantness, and a non-linear relationship between pleasantness and intensity was observed which reflects greater intensity for odors that elicit a strong hedonic response. The suitability of these data for use in future olfactory study is considered, and effective implementation of the data for controlling stimuli is discussed.

Past researchers of the integration of information in memory have typically required participants to attend to and/or commit to memory the stimuli conveying distinct features, rendering difficult the examination of whether the maintenance of the feature pairings can occur involuntarily. To address this issue, the integration of voice and location information in auditory sensory memory was measured using a cross-modal oddball task, in which task-irrelevant auditory deviants are known to capture attention in an involuntary fashion. Participants categorized visual digits presented shortly after to-be-ignored sounds. These sounds consisted in the same phoneme played simultaneously in both ears but in different voices (female in one ear, male in the other). On most trials, the pairing of voice to location was constant (standard sound). On rare and unpredictable trials, the voices swapped locations (deviant sound). In line with past work on attention capture by auditory novelty, the participants were significantly slower to judge the visual digits following the deviant sound, indicating the involuntary encoding of the links between voice and location in auditory memory. These results suggest that voices and locations are integrated in memory and that this binding occurs in conditions in which participants do not intend to commit any information to memory.