Look to the future but remember the past: A commentary on Ocklenburg, Berretz, Packheiser, and Friedrich (2020).

This is a commentary on a paper by Ocklenburg et al. ([2020]. Laterality 2020: entering the next decade. Laterality). I discuss measurement and task selection issues that should not be neglected as we make our way through the next decade. I also comment further on a few pointed issues relevant to open science and meta-analysis.

Auditory semantic priming and the dichotic right ear advantage.

The current study presents two experiments that aimed to explore the effects of auditory semantic priming on the dichotic right ear advantage. In Experiment 1, a classic fused dichotic words task was modified with the addition of auditory associative primes with three levels of relatedness (right, left, or neither ear). In Experiment 2, a new dichotic listening task was developed based on a binaural task used in a published auditory priming study. In both experiments, we expected that priming would produce a large right ear advantage when related to the right ear target but that the magnitude of this advantage would decrease for left ear related targets. Although evidence of priming (faster responses for related than unrelated primes) was found in both experiments, only Experiment 2 confirmed our prediction of an ear by prime relatedness interaction. Results are interpreted in the context of models concerned with the role of each cerebral hemisphere in semantic processing as well as models of perceptual asymmetries.

Perceptual asymmetries in a time estimation task with emotional sounds.

Four experiments investigated potential interactions between emotional content and perceptual asymmetries in the estimation of short time intervals. In all experiments, the word "bower" was presented monaurally to the left or right ear in an emotional tone and participants performed a temporal bisection task. In Experiment 1, angry and neutral stimuli ranged in duration from 260 to 440 ms (in steps of 20 ms) whereas in Experiments 2-4, durations ranged from 260 to 480 ms (in steps of 20 ms). In Experiment 3, the emotional tone of happiness replaced anger. In Experiment 4, anger and happiness were used as stimuli. In all experiments, results showed a larger bisection point for the right compared to the left ear. In addition, in all experiments, the constant error was farther away from zero for the right than for the left ear. The bisection point was also longer for the angry (Experiments 1 and 2) or happy (Experiment 3) than for the neutral emotional tone. Finally, happiness produced a shorter bisection point than anger in Experiment 4. Results are discussed in terms of their implications for time perception mechanisms and their potential cerebral representation.

Response procedure, memory, and dichotic emotion recognition.

Three experiments investigated the role of memory and rehearsal in a dichotic emotion recognition task by manipulating the response procedure as well as the interval between encoding and retrieval while taking into account order of report. For all experiments, right-handed undergraduates were presented with dichotic pairs of the words bower, dower, power, and tower pronounced in a sad, angry, happy, or neutral tone of voice. Participants were asked to report the two emotions presented on each trial by clicking on the corresponding drawings or words on a computer screen, either following no delay or a five second delay. Experiment 1 applied the delay conditions as a between-subjects factor whereas it was a within-subject factor in Experiment 2. In Experiments 1 and 2, more correct responses occurred for the left than the right ear, reflecting a left ear advantage (LEA) that was slightly larger with a nonverbal than a verbal response. The LEA was also found to be larger with no delay than with the 5s delay. In addition, participants typically responded first to the left ear stimulus. In fact, the first response produced a LEA whereas the second response produced a right ear advantage. Experiment 3 involved a concurrent task during the delay to prevent rehearsal. In Experiment 3, the pattern of results supported the claim that rehearsal could account for the findings of the first two experiments. The findings are interpreted in the context of the role of rehearsal and memory in models of dichotic listening.

Presaccadic Attention Enhances and Reshapes the Contrast Sensitivity Function Differentially around the Visual Field.

Contrast sensitivity (CS), which constrains human vision, decreases from fovea to periphery, from the horizontal to the vertical meridian, and from the lower vertical to the upper vertical meridian. It also depends on spatial frequency (SF), and the contrast sensitivity function (CSF) depicts this relation. To compensate for these visual constraints, we constantly make saccades and foveate on relevant objects in the scene. Already before saccade onset, presaccadic attention shifts to the saccade target and enhances perception. However, it is unknown whether and how it modulates the interplay between CS and SF, and if this effect varies around polar angle meridians. CS enhancement may result from a horizontal or vertical shift of the CSF, increase in bandwidth, or any combination. In addition, presaccadic attention could enhance CS similarly around the visual field, or it could benefit perception more at locations with poorer performance (i.e., vertical meridian). Here, we investigated these possibilities by extracting key attributes of the CSF of human observers. The results reveal that presaccadic attention (1) increases CS across SF, (2) increases the most preferred and the highest discernable SF, and (3) narrows the bandwidth. Therefore, presaccadic attention helps bridge the gap between presaccadic and postsaccadic input by increasing visibility at the saccade target. Counterintuitively, this CS enhancement was more pronounced where perception is better-along the horizontal than the vertical meridian-exacerbating polar angle asymmetries. Our results call for an investigation of the differential neural modulations underlying presaccadic perceptual changes for different saccade directions.

Neural Processing of Spectral and Durational Changes in Speech and Non-speech Stimuli: An MMN Study With Czech Adults.

Neural discrimination of auditory contrasts is usually studied via the mismatch negativity (MMN) component of the event-related potentials (ERPs). In the processing of speech contrasts, the magnitude of MMN is determined by both the acoustic as well as the phonological distance between stimuli. Also, the MMN can be modulated by the order in which the stimuli are presented, thus indexing perceptual asymmetries in speech sound processing. Here we assessed the MMN elicited by two types of phonological contrasts, namely vowel quality and vowel length, assuming that both will elicit a comparably strong MMN as both are phonemic in the listeners' native language (Czech) and perceptually salient. Furthermore, we tested whether these phonemic contrasts are processed asymmetrically, and whether the asymmetries are acoustically or linguistically conditioned. The MMN elicited by the spectral change between /a/ and /ε/ was comparable to the MMN elicited by the durational change between /ε/ and /ε:/, suggesting that both types of contrasts are perceptually important for Czech listeners. The spectral change in vowels yielded an asymmetrical pattern manifested by a larger MMN response to the change from /ε/ to /a/ than from /a/ to /ε/. The lack of such an asymmetry in the MMN to the same spectral change in comparable non-speech stimuli spoke against an acoustically-based explanation, indicating that it may instead have been the phonological properties of the vowels that triggered the asymmetry. The potential phonological origins of the asymmetry are discussed within the featurally underspecified lexicon (FUL) framework, and conclusions are drawn about the perceptual relevance of the place and height features for the Czech /ε/-/a/ contrast.

Inversion Reveals Perceptual Asymmetries in the Configural Processing of Human Body.

Ambiguous human bodies performing unimanual/unipedal actions are perceived more frequently as right-handed/footed rather than left-handed/footed, which suggests a perceptual and attentional bias toward the right side of others' body. A bias toward the right arm of human bodies could be adaptive in social life, most social interactions occurring with right-handed individuals, and the implicit knowledge that the dominant hand of humans is usually placed on their right side might also be included in body configural information. Given that inversion disrupts configural processing for human bodies, we investigated whether inversion reduces the bias toward the right side of human bodies. Consistent with our hypothesis, when presented with ambiguous stimuli depicting humans performing lateralized actions or movements, participants perceived a greater proportion of right-handed figures when the stimuli were shown upright than when the stimuli were shown inverted. The present findings seem to confirm our hypothesis that body configural information may include some form of knowledge about the probable handedness of other individuals, although alternative accounts involving the role of experience cannot be ruled out.

Behavioral Differences in the Upper and Lower Visual Hemifields in Shape and Motion Perception.

Perceptual accuracy is known to be influenced by stimuli location within the visual field. In particular, it seems to be enhanced in the lower visual hemifield (VH) for motion and space processing, and in the upper VH for object and face processing. The origins of such asymmetries are attributed to attentional biases across the visual field, and in the functional organization of the visual system. In this article, we tested content-dependent perceptual asymmetries in different regions of the visual field. Twenty-five healthy volunteers participated in this study. They performed three visual tests involving perception of shapes, orientation and motion, in the four quadrants of the visual field. The results of the visual tests showed that perceptual accuracy was better in the lower than in the upper visual field for motion perception, and better in the upper than in the lower visual field for shape perception. Orientation perception did not show any vertical bias. No difference was found when comparing right and left VHs. The functional organization of the visual system seems to indicate that the dorsal and the ventral visual streams, responsible for motion and shape perception, respectively, show a bias for the lower and upper VHs, respectively. Such a bias depends on the content of the visual information.

Peripheral vision, perceptual asymmetries and visuospatial attention in young, young-old and oldest-old adults.

OBJECTIVES: The present study investigated possible changes occurring in peripheral vision, perceptual asymmetries and visuospatial attention in oldest-old adults and compared their performance with that of young and young-old adults. METHOD: We examined peripheral vision (PV) and perceptual asymmetries in the three age groups for stimuli varying in eccentricity (Experiment 1). In Experiment 2, designed to investigate possible changes in spatial attention, the same participants performed an exogenous orienting attention task. RESULTS: Experiment 1 showed that the three age groups performed the task similarly but differed in processing speed. Importantly, the oldest-old group showed a different perceptual pattern than the other groups suggesting a lack of specificity in visual asymmetries. Experiment 2 indicated that the validity effects emerged later in the young-old and even later in the oldest-old participants, showing a delayed time course of inhibition of return (IOR). Orienting effects, however, were preserved with age. DISCUSSION: Taken together, these results indicate that the three age groups displayed similar perceptual and orienting attention patterns, but with differences in processing speed. Importantly, age (only in the oldest-old adults) altered perceptual visual asymmetries. These results suggest that some neural plasticity is still present even in oldest-old adults, but a lack of specificity occurs in advanced age.

Behavioural asymmetries on the greyscales task: The influence of native reading direction.

Reliable leftward attentional and perceptual biases demonstrated in a variety of visuospatial tasks have been found to deviate from the left in research examining the influence of scanning habits. The aim of the current research was to examine the influence of native script direction on pseudoneglect during the greyscales task in a representative sample of native right-to-left readers. Fifty-four native left-to-right readers and 43 right-to-left readers completed the greyscales task, which required judging the darker of two left-right mirrored brightness gradients. Native left-to-right readers demonstrated a left response bias on the greyscales task, whereas right-to-left readers failed to demonstrate a bias, however, both groups responded more quickly when making leftward choices. The research suggests that the strength of attentional biases are influenced by behavioural biases, such as scanning habits, and neural and anatomical asymmetries in the right parietal and frontal cortices. Thus, to improve the clinical utility of the greyscales task for diagnosing neglect, right-to-left readers should be examined to fully understand the normal range of biases displayed by neurologically healthy individuals.