Complementary interactions between classical and top-down driven inhibitory mechanisms of attention

Selective attention informs decision-making by biasing perceptual processing towards task-relevant stimuli. In experimental and computational literature, this is most often implemented through top-down excitation of selected stimuli. However, physiological and anatomical evidence shows that in certain situations, top-down signals could instead be inhibitory. In this study, we investigated how such an inhibitory mechanism of top-down attention compares with an excitatory one. We did so in a neurorobotics context where the agent was controlled using an established hierarchical architecture. We augmented the architecture with an attentional system that implemented top-down attention biasing as connection gains. We tested four models of top-down attention on the simulated agent performing a foraging task: without top-down biasing, with only excitatory top-down gain, with only inhibitory top-down gain, and with both excitatory and inhibitory top-down gain. We manipulated the reward-distractor ratio that was presented and assessed the agent's performance using accumulated rewards and the latency of the selection. Using these measures, we provide evidence that excitatory and inhibitory mechanisms of attention complement each other.     

Adjectives Modulate Sensorimotor Activation Driven by Nouns

We performed three experiments to investigate whether adjectives can modulate the sensorimotor activation elicited by nouns. In Experiment 1, nouns of graspable objects were used as stimuli. Participants had to decide if each noun referred to a natural or artifact, by performing either a precision or a power reach-to-grasp movement. Response grasp could be compatible or incompatible with the grasp typically used to manipulate the objects to which the nouns referred. The results revealed faster reaction times (RTs) in compatible than in incompatible trials. In Experiment 2, the nouns were combined with adjectives expressing either disadvantageous information about object graspability (e.g., sharp) or information about object color (e.g., reddish). No difference in RTs between compatible and incompatible conditions was found when disadvantageous adjectives were used. Conversely, a compatibility effect occurred when color adjectives were combined with nouns referring to natural objects. Finally, in Experiment 3 the nouns were combined with adjectives expressing tactile or shape proprieties of the objects (e.g., long or smooth). Results revealed faster RTs in compatible than in incompatible condition for both noun categories. Taken together, our findings suggest that adjectives can shape the sensorimotor activation elicited by nouns of graspable objects, highlighting that language simulation goes beyond the single-word level.     

Comparing the efficacy (RCT) of learning a dance choreography and practicing creative dance on improving executive functions and motor competence in 6–7 years old children

ObjectivesThis study examined the effect of two different dance curriculums on executive functions and motor competence in 6–7 years old primary-school children across an 8-week period. One dance curriculum was underscored by creativity and the other was based on a choreographed dancing curriculum with high cognitive challenge.DesignRandomised-controlled trial.MethodsSixty-two primary-school children (6.6 ± 0.5 years old; 47% females) participated for a control period in the regular school PE lessons, after which they were randomly assigned to two experimental groups – choreography dance group or creative dance group. The two experimental groups practiced dance for 8 weeks, twice a week, learning either a choreographed dance sequence with high cognitive challenge or creating their own dance sequence in a creative dance curriculum. Executive functions (working memory capacity, inhibition, and flexibility) and motor competence were assessed at three time points – baseline, pre-intervention and post-intervention.ResultsThere was a time effect for inhibitory control (p < 0.01), with a high improvement during the intervention (d = 0.76) than baseline (d = 0.46); for working memory capacity (p < 0.01), with a higher improvement during intervention (d = 0.43) than baseline (d = 0.31) in the high challenging task; and for motor competence (p < 0.01), with a higher improvement during baseline (d = 1.7) than intervention (d = 0.75); no other significant effects. Group differences revealed weak evidence that the choreography group improved inhibitory control and working memory more than the creative dance group. However, a check for pedagogy fidelity revealed that the creative-dance curriculum was not adopted as planned (i.e., high volume of teacher's instruction and small use of music).ConclusionsAn 8-week dance intervention improved inhibitory control and potentially working memory capacity in grade one and two primary-school children. Contrary to prediction, the dance intervention did not improve motor competence beyond typical development. Discrepancy between the planned and adopted creative-dance curriculum suggests caution in interpreting results. This study provides new insights into the exercise-cognition relationship.     

Turing redux: Enculturation and computation

Many of our cognitive capacities are shaped by enculturation. Enculturation is the acquisition of cognitive practices such as symbol-based mathematical practices, reading, and writing during ontogeny. Enculturation is associated with significant changes to the organization and connectivity of the brain and to the functional profiles of embodied actions and motor programs. Furthermore, it relies on scaffolded cultural learning in the cognitive niche. The purpose of this paper is to explore the components of symbol-based mathematical practices. Phylogenetically, these practices are the result of concerted organism-niche interactions that have led from approximate number estimations to the emergence of discrete, symbol-based mathematical operations. Ontogenetically, symbol-based mathematical practices are associated with plastic changes to neural circuitry, action schemata, and motor programs. It will be suggested that these practices rely on previously acquired capacities such as subitizing and counting. With these considerations in place, I will argue that computations, understood in the sense of Turing (1936), are a specific kind of symbol-based mathematical practices that can be realized by human organisms, machines, or by hybrid organism-machine systems. In sum, this paper suggests a new way to think about mathematical cognition and computation.     

Being (un)moved by mental time travel

Mental imagery of events in the past or future, and of unpleasant or pleasant events, has been found to lead to spontaneous backward/forward bodily motions. Both time and emotion are represented along a spatial continuum, and activation of these representations seems to be simulated in spontaneous changes in body posture. We performed a conceptual replication and extension of an earlier study by Miles, Nind, and Macrae (2010) who reported clear postural effects when thinking of the past and the future. We additionally tested whether changes in posture appear when thinking of an emotional event. Volunteers engaged in mental imagery, involving combinations of time intervals and emotions. We simultaneously recorded center-of-pressure (COP) changes. Results revealed neither an effect of imagery of time nor of emotion on body posture. We conclude that embodied effects of imagery of abstract items on body posture may be less robust than suggested by previous literature.     

The embodiment of beauty: Evidence from viewing Chinese concrete words and pictographs

How is beauty embodied? According to the viewpoint of embodied cognition, the aesthetic processing of words or pictographs has roots in their referential archetypes. Four experiments tested whether the beauty of referential archetypes was routinely activated during the explicit and implicit aesthetic evaluations of the font structures of concrete Chinese words and pictographs in congruent or incongruent font colour. Results showed font structures of simplified Chinese words and pictographs were judged to be more beautiful when they referred to beautiful archetypes; and this pattern was reversed when they referred to ugly archetypes. Moreover, judgement was facilitated when font colour was congruent for Chinese words and pictographs referred to beautiful archetypes. For those referred to ugly archetypes, judgement was inhibited in congruent font colour but facilitated in incongruent font colour, suggesting aesthetic perceptions of the font structures of Chinese words and pictographs were derived from their referential natural objects. The spontaneous generation hypothesis of beauty is proposed to account for these findings.     

Body posture facilitates retrieval of autobiographical memories

We assessed potential facilitation of congruent body posture on access to and retention of autobiographical memories in younger and older adults. Response times were shorter when body positions during prompted retrieval of autobiographical events were similar to the body positions in the original events than when body position was incongruent. Free recall of the autobiographical events two weeks later was also better for congruent-posture than for incongruent-posture memories. The findings were similar for younger and older adults, except for the finding that free recall was more accurate in younger adults than in older adults in the congruent condition. We discuss these findings in the context of theories of embodied cognition.     

Representing object colour in language comprehension

Embodied theories of cognition hold that mentally representing something red engages the neural subsystems that respond to environmental perception of that colour. This paper examines whether implicit perceptual information on object colour is represented during sentence comprehension even though doing so does not necessarily facilitate task performance. After reading a sentence that implied a particular colour for a given object, participants were presented with a picture of the object that either matched or mismatched the implied colour. When asked if the pictured object was mentioned in the preceding sentence, people's responses were faster when the colours mismatched than when they matched, suggesting that object colour is represented differently to other object properties such as shape and orientation. A distinction between stable and unstable embodied representations is proposed to allow embodied theories to account for these findings.     

The effect of psychological distance on perceptual level of construal

Three studies examined the effect of primed psychological distance on level of perceptual construal, using Navon's paradigm of composite letters (global letters that are made of local letters). Relative to a control group, thinking of the more distant future (Study 1), about more distant spatial locations (Study 2), and about more distant social relations (Study 3) facilitated perception of global letters relative to local letters. Proximal times, spatial locations, and social relations had the opposite effect. The results are discussed within the framework of Construal Level Theory of psychological distance ( Liberman & Trope, 2008 ; Trope & Liberman, 2003 ).     

Tactile Enumeration and Embodied Numerosity Among the Deaf

Representations of the fingers are embodied in our cognition and influence performance in enumeration tasks. Among deaf signers, the fingers also serve as a tool for communication in sign language. Previous studies in normal hearing (NH) participants showed effects of embodiment (i.e., embodied numerosity) on tactile enumeration using the fingers of one hand. In this research, we examined the influence of extensive visuo-manual use on tactile enumeration among the deaf. We carried out four enumeration task experiments, using 1–5 stimuli, on a profoundly deaf group (n = 16) and a matching NH group (n = 15): (a) tactile enumeration using one hand, (b) tactile enumeration using two hands, (c) visual enumeration of finger signs, and (d) visual enumeration of dots. In the tactile tasks, we found salient embodied effects in the deaf group compared to the NH group. In the visual enumeration of finger signs task, we controlled the meanings of the stimuli presentation type (e.g., finger-counting habit, fingerspelled letters, both or neither). Interestingly, when comparing fingerspelled letters to neutrals (i.e., not letters or numerical finger-counting signs), an inhibition pattern was observed among the deaf. The findings uncover the influence of rich visuo-manual experiences and language on embodied representations. In addition, we propose that these influences can partially account for the lag in mathematical competencies in the deaf compared to NH peers. Lastly, we further discuss how our findings support a contemporary model for mental numerical representations and finger-counting habits.