The anisochrony of a stimulus sequence was manipulated parametrically to investigate whether rhythmic entrainment is stronger in the auditory modality than in the visual modality (Experiment 1), and whether it relies on top-down attention (Experiment 2). In Experiment 1, participants had to respond as quickly as possible to a target presented after a sequence of either visual or auditory stimuli. The anisochrony of this sequence was manipulated parametrically, rather than in an all or none fashion; that is, it could range from smaller to larger deviations of the isochrony (0, 10, 20, 50, 100, 150 and 200 ms). We compared rhythmic entrainment patterns for auditory and visual modalities. Results showed a peak of entrainment for both isochrony and deviations of isochrony up to 50 ms (i.e., participants were equally fast both after the isochronous sequences and after 10, 20 and 50 ms deviations), suggesting that anisochronous sequences can also produce entrainment. Beyond this entrainment window, the reaction times became progressively slower. Surprisingly, no differences were found between the entrainment patterns for auditory and visual rhythms. In Experiment 2, we used a dual-task methodology by adding a working memory n-back task to the procedure of Experiment 1. Results did not show interference of the secondary task in either auditory or visual modalities, with participants showing the same entrainment pattern as in Experiment 1. These results suggest that rhythmic entrainment constitutes a cognitive process that occurs by default (automatically), regardless of the modality in which the stimuli are presented, and independent of top-down attention, to generate behavioural benefits.
Context dependence of information has been shown to be based, at least in part, on the attention contexts received at the time of training. Recent research suggests that attention to irrelevant contexts may be a byproduct of the activation of a general exploratory attentional mechanism prompted by high prediction errors associated with situations of uncertainty. Alternatively, low prediction errors may engage an attentional mechanism of exploitation in situations in which contexts play a relevant role. A selective review discusses the potential of this approach to explain context switch effects from an attentional perspective.
Laura Puigcerver, Sara Rodríguez-Cuadrado, Víctor Gómez-Tapia and Jordi Navarra
Although the perceptual association between verticality and pitch has been widely studied, the link between loudness and verticality is not fully understood yet. While loud and quiet sounds are assumed to be equally associated crossmodally with spatial elevation, there are perceptual differences between the two types of sounds that may suggest the contrary. For example, loud sounds tend to generate greater activity, both behaviourally and neurally, than quiet sounds. Here we investigated whether this difference percolates into the crossmodal correspondence between loudness and verticality. In an initial phase, participants learned one-to-one arbitrary associations between two tones differing in loudness (82dB vs. 56dB) and two coloured rectangles (blue vs. yellow). During the experimental phase, they were presented with the two-coloured stimuli (each one located above or below a central “departure” point) together with one of the two tones.
Participants had to indicate which of the two-coloured rectangles corresponded to the previously-associated tone by moving a mouse cursor from the departure point towards the target. The results revealed that participants were significantly faster responding to the loud tone when the visual target was located above (congruent condition) than when the target was below the departure point (incongruent condition). For quiet tones, no differences were found between the congruent (quiet-down) and the incongruent (quiet-up) conditions. Overall, this pattern of results suggests that possible differences in the neural activity generated by loud and quiet sounds influence the extent to which loudness and spatial elevation share representational content.
Sixteen naïve male Wistar rats were exposed to intermittent food delivery to measure the development of schedule-induced wheel running, using fixed time (FT) 30, 60, 120, 240 and 480 s schedules, counterbalanced across animals according to a Latin square design (except under the FT 480 s, which was always presented last to complete the data set). Rats were also exposed to a massed-food control condition. Wheel running was induced in the range of 30-240 s with a gradation as a function of inter-food interval (IFI) length. The temporal distribution of wheel turns was generally presented in the form of an inverted U-shaped as IFIs progressed, showing maximum responding during the first portion of the interval. The introduction of massed-food resulted in an immediate reduction in wheel running. These results support the notion that wheel running can be schedule-induced and categorized into the so-called adjunctive behaviors. These data indicate that IFI length affects the development of schedule-induced wheel running and that the rate of wheel running is maintained by intermittent reinforcement, which are common characteristics of schedule-induced behaviors. Likewise, this idea is supported by the occurrence of a similar temporal pattern to that found with other adjunctive behaviors, such as schedule-induced polydipsia, with its maximum manifestation occurring between the beginning and middle of IFIs.
Whether bilingualism has an effect on the executive function of non-verbal representations is probably one of the most controversial issues in cognitive psychology and cognitive neuroscience. As bilinguals have to alternate between two languages that compete for selection in their daily lives, they make use of selection, inhibition, and monitoring (i.e., components of executive function) more often than monolinguals. Thus, it would not be surprising that these highly trained abilities at selecting and monitoring the linguistic processes would also help the processing of non-linguistic representations. Although the “bilingual advantage” in executive control (Bialystok, 1999) has been repeatedly demonstrated, a number of recent studies—in particular since the publication of the Paap and Greenberg (2013) study—have questioned this effect. Both positive and null findings are currently being published from each of the two sides, thus making it difficult to reach consensus in the scientific community. Here, we propose a plausible solution to this debate: a group of independent researches should carry out a carefully planned large-scale study.
Amin Ghamari, Mehdi Sohrabi and Alireza Saberi Kakhki
Depending on the difficulty of the task in terms of movement duration and the number of elements forming the sequence, recent research has shown that movement sequences are coded in visual-spatial coordinates or motor coordinates. An interesting question that arises is how a specific manner of performance without a change in such functional difficulties affects the representation of movement sequences. Accordingly, the present study investigated how the way in which a movement sequence is performed affects the transfer of timing properties (absolute and relative timing) from the practised to unpractised hand under mirror (same motor commands as those used in practice) and non-mirror (the same visual-spatial coordinates as those present during practice) conditions in two experiments each with segment movement time goals that were arranged differently. The study showed that after a limited amount of practice, the pattern of results obtained for relative timing differed between the two experiments. In the first experiment, there was no difference between retention and non-mirror transfer, but performance on these tasks was significantly better than that for mirror transfer, whereas in the second experiment, there was no difference between the mirror and non-mirror transfer. For total errors, no significant difference was found between the retention and transfer tests in both experiments. It was concluded that the way in which a sequence is performed could affect the representation of the task and the transfer of relative timing, while absolute timing could purposefully be maintained if necessary.