Audiovisual integration capacity modulates as a function of illusory visual contours, visual display circumference, and sound type

Research into the capacity of audiovisual integration has previously assessed whether capacity is strictly limited to a single item, or whether it can exceed one item under certain environmental conditions. More recently, investigations have turned to examining the effects of various stimulus factors on capacity. Across two experiments, we looked at a number of factors that were expected to play a modulatory role on capacity. Experiment 1 deployed a manipulation of illusory polygons, revealing an increase in audiovisual capacity, even in an absence of visual connections. This demonstrates that exceeding the capacity of 1 does not only represent a functional increase in the binding of a singular, complex visual object, but that it can also represent binding of multiple simpler objects. Findings also support the hypothesis that capacity modulates quantitatively, but not qualitatively, with respect to speed of presentation. Experiment 2 examined the effects of different sound types (sine tones or white noise) and of different spatial visual field sizes on the capacity of audiovisual integration. The results indicated that capacity is maximized when stimuli are presented in a smaller circle (7.5°) if alongside a sine tone, and when presented in a larger circle (18.5°) alongside a white noise. These results suggest that audiovisual integration capacity is dependent on the combination of sound type and visual spatial field size. The combination of these results reveal additional phenomenological features of the capacity of audiovisual integration, and provides impetus for further research into applications of the findings.

“Judging a Book by Its Cover”: The Dominance of Delivery Over Content When Perceiving Charisma

Perceived charisma is an outcome of message content and delivery, where the latter dominates the former. Framing perception of charisma within dual-process theories, we suggest a rapid processing of delivery and a slow processing of content. We aimed to track the differential processing speed of content and delivery that accounts for the delivery dominance. In two laboratory experiments, we manipulated content and delivery. Participants reported perceived charisma after viewing a presentation (Experiment 1) or moment-by-moment during the presentation (Experiment 2). The results confirmed the immediate influence of delivery on perceived charisma that was later either supported or revised by the content. Theoretical and practical implications of the findings are discussed.

Probing Communication-Induced Memory Biases in Preverbal Infants: Two Replication Attempts of Yoon, Johnson and Csibra (2008)

In a seminal study, Yoon, Johnson and Csibra [PNAS, 105, 36 (2008)] showed that nine-month-old infants retained qualitatively different information about novel objects in communicative and non-communicative contexts. In a communicative context, the infants encoded the identity of novel objects at the expense of encoding their location, which was preferentially retained in non-communicative contexts. This result has not yet been replicated. Here we attempted two replications, while also including a measure of eye-tracking to obtain more detail of infants’ attention allocation during stimulus presentation. Experiment 1 was designed following the methods described in the original paper. After discussion with one of the original authors, some key changes were made to the methodology in Experiment 2. Neither experiment replicated the results of the original study, with Bayes Factor Analysis suggesting moderate support for the null hypothesis. Both experiments found differential attention allocation in communicative and non-communicative contexts, with more looking to the face in communicative than non-communicative contexts, and more looking to the hand in non-communicative than communicative contexts. High and low level accounts of these attentional differences are discussed.

Spatial suppression due to statistical regularities is driven by distractor suppression not by target activation

Where and what we attend to is not only determined by what we are currently looking for but also by what we have encountered in the past. Recent studies suggest that biasing the probability by which distractors appear at locations in visual space may lead to attentional suppression of high probability distractor locations which effectively reduces capture by a distractor but also impairs target selection at this location. However, in many of these studies introducing a high probability distractor location was tantamount to increasing the probability of the target appearing in any of the other locations (i.e. the low probability distractor locations). Here, we investigate an alternative interpretation of previous findings according to which attentional selection at high probability distractor locations is not suppressed. Instead, selection at low probability distractor locations is facilitated. In two visual search tasks, we found no evidence for this hypothesis: neither when there was only a bias in target presentation but no bias in distractor presentation (Experiment 1), nor when there was only a bias in distractor presentation but no bias in target presentation (Experiment 2). We conclude that recurrent presentation of a distractor in a specific location leads to attentional suppression of that location through a mechanism that is unaffected by any regularities regarding the target location.

Exploring Use of the Coordinate Response Measure in a Multitalker Babble Paradigm

Purpose Three experiments examined the use of competing coordinate response measure (CRM) sentences as a multitalker babble. Method In Experiment I, young adults with normal hearing listened to a CRM target sentence in the presence of 2, 4, or 6 competing CRM sentences with synchronous or asynchronous onsets. In Experiment II, the condition with 6 competing sentences was explored further. Three stimulus conditions (6 talkers saying same sentence, 1 talker producing 6 different sentences, and 6 talkers each saying a different sentence) were evaluated with different methods of presentation. Experiment III examined the performance of older adults with hearing impairment in a subset of conditions from Experiment II. Results In Experiment I, performance declined with increasing numbers of talkers and improved with asynchronous sentence onsets. Experiment II identified conditions under which an increase in the number of talkers led to better performance. In Experiment III, the relative effects of the number of talkers, messages, and onset asynchrony were the same for young and older listeners. Conclusions Multitalker babble composed of CRM sentences has masking properties similar to other types of multitalker babble. However, when the number of different talkers and messages are varied independently, performance is best with more talkers and fewer messages.

Dynamic Frequencies and Perceptual Binding in a Combined Auditory-Tactile Task

Two experiments examined the potential effect of perceptual binding in the auditory and tactile modalities for one stimulus parameter: dynamic frequency sweeps versus static frequencies. Experiment 1 established baseline performance for identifying a single stimulus presentation. Experiment 2 examined the effects of presenting simultaneous auditory and tactile signals while attempting to focus on a single sensory channel. Experiment 1 demonstrates that identifying the frequency sweep or static signal is relatively easy in both modalities. Experiment 2 shows the unidirectional domination of auditory signals over tactile, irrespective of sensory focus modality. Overall findings and the implications for design and directions for future research are discussed.

The Basis and Implications of the Restoration of a Recency Effect in Immediate Serial Recall

When a spoken presentation of a supra-span sequence of to-be-remembered (TBR) items is followed immediately by a similarly-spoken non-TBR item (stimulus suffix) the typical salience of the terminal item in recall is almost destroyed. However, Salter (1975) observed restoration of salience when pre-terminal and terminal TBR items differed in category membership. Five experiments are reported which aimed to clarify the basis and locus of Salter's effect. Survival of salience for the heterogeneous item was found under the following conditions: with the occurrence of the item unpredictable from trial-to-trial (Experiment I); with enforced processing of the suffix (Experiment II); with performance of a secondary task during list presentation (Experiment III); with the requirement to retain both the location and identity of the item (Experiment IV); and with the item as the terminal member of a non-suffixed visual list (Experiment V). It is argued that the effect has a postcategorical locus, and that its origin is not in better registration (mediated by selective attention), but, rather, in the enhancement of retrieval (mediated by access to distinctive information encoded during presentation). It is suggested that the latter hypothesis may have wide application in accounting for many kinds of salience.