Tool heads prime saccades

Is there a lower visual field advantage for object affordances? A registered report

It's been repeatedly shown that pictures of graspable objects can facilitate visual processing, even in the absence of reach-to-grasp actions, an effect often attributed to the concept of affordances. A classic demonstration of this is the handle compatibility effect, characterised by faster reaction times when the orientation of a graspable object's handle is compatible with the hand used to respond, even when the handle orientation is task-irrelevant. Nevertheless, it is debated whether the speeded reaction times are a result of affordances or spatial compatibility. First, we investigated whether we could replicate the handle compatibility effect while controlling for spatial compatibility. Participants (N = 68) responded with left or right-handed keypresses to whether the object was upright or inverted and, in separate blocks, whether the object was red or green. We failed to replicate the handle compatibility effect, with no significant difference between compatible and incompatible conditions, in both tasks. Second, we investigated whether there is a lower visual field (VF) advantage for the handle compatibility effect in line with what has been found for hand actions. A further 68 participants responded to object orientation presented either in the upper or lower VF. A significant handle compatibility effect was observed in the lower VF, but not the upper VF. This suggests that there is a lower VF advantage for affordances, possibly as the lower VF is where our actions most frequently occur. However, future studies should explore the impact of eye movements on the handle compatibility effect and tool affordances.

On the functional brain networks involved in tool-related action understanding

Tool-use skills represent a significant cognitive leap in human evolution, playing a crucial role in the emergence of complex technologies. Yet, the neural mechanisms underlying such capabilities are still debated. Here we explore with fMRI the functional brain networks involved in tool-related action understanding. Participants viewed images depicting action-consistent (e.g., nail-hammer) and action-inconsistent (e.g., scarf-hammer) object-tool pairs, under three conditions: semantic (recognizing the tools previously seen in the pairs), mechanical (assessing the usability of the pairs), and control (looking at the pairs without explicit tasks). During the observation of the pairs, task-based left-brain functional connectivity differed within conditions. Compared to the control, both the semantic and mechanical conditions exhibited co-activations in dorsal (precuneus) and ventro-dorsal (inferior frontal gyrus) regions. However, the semantic condition recruited medial and posterior temporal areas, whereas the mechanical condition engaged inferior parietal and posterior temporal regions. Also, when distinguishing action-consistent from action-inconsistent pairs, an extensive frontotemporal neural circuit was activated. These findings support recent accounts that view tool-related action understanding as the combined product of semantic and mechanical knowledge. Furthermore, they emphasize how the left inferior parietal and anterior temporal lobes might be considered as hubs for the cross-modal integration of physical and conceptual knowledge, respectively.

Investigating the cognitive processing of tools: Effects of dangerousness and directionality on attentional biases

Research has found a tool-based head-superiority effect (responses are faster to target stimuli that appear at the head than at the handle position). However, these studies did not consider the effects of directionality and dangerousness. This study investigated how directionality and dangerousness influence the head-superiority effect. Subjects were required to respond to the target location in all experiments. Experiment 1 manipulated the directionality, dangerousness and target location. Experiment 2 matched the sharpness of the tool tip in the directed conditions. Experiment 3 shortened the presentation time of the cue stimuli from 800 ms to 200 ms. Experiment 4 selected four tools with different functions to rule out an alternative explanation caused by functional repetition. The results indicate that a head-superiority effect emerges in the directed condition, and that dangerousness modulates the magnitude of this effect during the 800 ms condition. However, the modulation effect of dangerousness diminishes during the 200 ms condition.

Cognitive Archeology and the Attentional System: An Evolutionary Mismatch for the Genus Homo

Brain evolution is a key topic in evolutionary anthropology. Unfortunately, in this sense the fossil record can usually support limited anatomical and behavioral inferences. Nonetheless, information from fossil species is, in any case, particularly valuable, because it represents the only direct proof of cerebral and behavioral changes throughout the human phylogeny. Recently, archeology and psychology have been integrated in the field of cognitive archeology, which aims to interpret current cognitive models according to the evidence we have on extinct human species. In this article, such evidence is reviewed in order to consider whether and to what extent the archeological record can supply information regarding changes of the attentional system in different taxa of the human genus. In particular, behavioral correlates associated with the fronto-parietal system and working memory are employed to consider recent changes in our species, Homo sapiens, and a mismatch between attentional and visuospatial ability is hypothesized. These two functional systems support present-moment awareness and mind-wandering, respectively, and their evolutionary unbalance can explain a structural sensitivity to psychological distress in our species.

The robot eyes don't have it. The presence of eyes on collaborative robots yields marginally higher user trust but lower performance

Eye gaze is a prominent feature of human social lives, but little is known on whether fitting eyes on machines makes humans trust them more. In this study we compared subjective and objective markers of human trust when collaborating with eyed and non-eyed robots of the same type. We used virtual reality scenes in which we manipulated distance and the presence of eyes on a robot's display during simple collaboration scenes. We found that while collaboration with eyed cobots resulted in slightly higher subjective trust ratings, the objective markers such as pupil size and task completion time indicated it was in fact less comfortable to collaborate with eyed robots. These findings are in line with recent suggestions that anthropomorphism may be actually a detrimental feature of collaborative robots. These findings also show the complex relationship between human objective and subjective markers of trust when collaborating with artificial agents.

Virtual Reality for Safe Testing and Development in Collaborative Robotics: Challenges and Perspectives

Collaborative robots (cobots) could help humans in tasks that are mundane, dangerous or where direct human contact carries risk. Yet, the collaboration between humans and robots is severely limited by the aspects of the safety and comfort of human operators. In this paper, we outline the use of extended reality (XR) as a way to test and develop collaboration with robots. We focus on virtual reality (VR) in simulating collaboration scenarios and the use of cobot digital twins. This is specifically useful in situations that are difficult or even impossible to safely test in real life, such as dangerous scenarios. We describe using XR simulations as a means to evaluate collaboration with robots without putting humans at harm. We show how an XR setting enables combining human behavioral data, subjective self-reports, and biosignals signifying human comfort, stress and cognitive load during collaboration. Several works demonstrate XR can be used to train human operators and provide them with augmented reality (AR) interfaces to enhance their performance with robots. We also provide a first attempt at what could become the basis for a human–robot collaboration testing framework, specifically for designing and testing factors affecting human–robot collaboration. The use of XR has the potential to change the way we design and test cobots, and train cobot operators, in a range of applications: from industry, through healthcare, to space operations.

Perceived depth modulates perceptual resolution

Humans constantly use depth information to support perceptual decisions about object size and location in space, as well as planning and executing actions. It was recently reported that perceived depth modulates perceptual performance even when depth information is not relevant to the task, with faster shape discrimination for objects perceived as being close to the observer. However, it is yet to be determined if the observed "close advantage" reflects differences in psychophysical sensitivity or response bias. Moreover, it is unclear whether this advantage is generalizable to other viewing situations and tasks. To address these outstanding issues, we evaluated whether visual resolution is modulated by perceived depth defined by 2D pictorial cues. In a series of experiments, we used the method of constant stimuli to measure the precision of perceptual judgements for stimuli positioned at close, far, and flat perceived distances. In Experiment 1, we found that size discrimination was more precise when the object was perceived to be closer to the observers. Experiments 2a and 2b extended this finding to a visual property orthogonal to depth information, by showing superior orientation discrimination for "close" objects. Finally, Experiment 3 demonstrated that the close advantage also occurs when performing high-level perceptual tasks such as face perception. Taken together, our results provide novel evidence that the perceived depth of an object, as defined by pictorial cues, modulates the precision of visual processing for close objects.

Practice and transfer with mappings of spoon tip and handle to keypress responses

When orientation of a horizontal spoon image varies to the left or right, instructions can map left and right keypresses to the tip or handle location. We conducted Experiment 1 to determine whether practice with an incompatible mapping of the salient tip transfers to a test session in which the relevant part and/or mapping are changed. Participants performed 80 practice trials with tip-incompatible mapping, followed by 80 test trials with tip-compatible, tip-incompatible, handle-compatible, or handle-incompatible mapping. Performance improved across 20-trial blocks in the practice session. In the test session, responses were 65 ms faster with tip-compatible than tip-incompatible mapping but 31 ms faster with handle-incompatible than handle-compatible mapping. This latter result, and verbal reports, indicate that some participants adopted a strategy of responding compatibly to the salient tip even though instructed to respond to the handle. Experiment 2 focused on whether participants with handle-incompatible mapping instructions would adopt the tip-compatible strategy spontaneously or after receiving a hint: 77% of participants reported adopting the tip-compatible strategy in Session 1, showing that prior experience responding to the tip is not necessary and 9% of participants did not report using that strategy in Session 1 but reported changing to it in Session 2 after receiving the hint. Their responses in Session 2 were slower than those who used the strategy throughout, but this difference was minimal in the last two trial blocks. Compatible mapping of the salient spoon tip to keypresses dominated performance over prior practice with incompatible tip mapping and instructions with incompatible handle mapping.