Eye position modulates retinotopic responses in early visual areas: a bias for the straight-ahead direction

Even though the eyes constantly change position, the location of a stimulus can be accurately represented by a population of neurons with retinotopic receptive fields modulated by eye position gain fields. Recent electrophysiological studies, however, indicate that eye position gain fields may serve an additional function since they have a non-uniform spatial distribution that increases the neural response to stimuli in the straight-ahead direction. We used functional magnetic resonance imaging and a wide-field stimulus display to determine whether gaze modulations in early human visual cortex enhance the blood-oxygenation-level dependent (BOLD) response to stimuli that are straight-ahead. Subjects viewed rotating polar angle wedge stimuli centered straight-ahead or vertically displaced by ±20° eccentricity. Gaze position did not affect the topography of polar phase-angle maps, confirming that coding was retinotopic, but did affect the amplitude of the BOLD response, consistent with a gain field. In agreement with recent electrophysiological studies, BOLD responses in V1 and V2 to a wedge stimulus at a fixed retinal locus decreased when the wedge location in head-centered coordinates was farther from the straight-ahead direction. We conclude that stimulus-evoked BOLD signals are modulated by a systematic, non-uniform distribution of eye-position gain fields

The welfare of water buffaloes during the slaughter process: a review

This paper reviews the scientific literature on water buffalo welfare in all stages of the live animal supply chain from the farm gate to slaughter (loading/unloading, markets, transportation, handling, lairage, stunning and slaughter) with the objective of identifying risk factors and potential mitigation strategies. Although in some countries legislation exists to protect the welfare of farm animals during transport and killing, the handling practices used to load and unload buffaloes and move them in livestock markets and abattoirs are often harsh. This is frequently due to inadequate equipment designed principally for cattle, and the fact that water buffaloes are considered more temperamental than cattle. Additionally, more reactive animals have increased stress responses to handling, which can lead to more negative human interventions with increased numbers of skin lesions and bruises to the carcasses. During transport, buffaloes may suffer periods of thermal stress due to overstocking, inadequate ventilation and because in many tropical climates trips are made during the hottest time of the day. The anatomical and physiological characteristics of water buffalo make them particularly susceptible to thermal stress in the absence of water for wallowing. Although water buffaloes belong to the same Bovidae family as domestic cattle, certain anatomical features of the head make effective stunning very problematic. Buffaloes have extensive sinuses and frontal bones, meaning that the penetrating captive bolt devices recommended for cattle may prove ineffective in reliably inducing unconsciousness. There is a need for further development of procedures, stunning positions and appropriate devices to improve the efficiency of buffalo stunning. Finally, in many parts of the world where buffalo are routinely slaughtered in basic conditions without prior stunning. Slaughter without stunning can result in pain and stress associated with delays in the time to loss of consciousness, pain from the cutting of the neck and potential distress associated with aspiration of blood into the respiratory tract. Specific legislation, guidelines and handler/stockman/operator training programmes should be developed to improve the welfare of buffaloes during all ante mortem stages of loading, unloading, handling, stunning and slaughter

Spatio-Temporal Brain Mapping of Motion-Onset VEPs Combined with fMRI and Retinotopic Maps

Neuroimaging studies have identified several motion-sensitive visual areas in the human brain, but the time course of their activation cannot be measured with these techniques. In the present study, we combined electrophysiological and neuroimaging methods (including retinotopic brain mapping) to determine the spatio-temporal profile of motion-onset visual evoked potentials for slow and fast motion stimuli and to localize its neural generators. We found that cortical activity initiates in the primary visual area (V1) for slow stimuli, peaking 100 ms after the onset of motion. Subsequently, activity in the mid-temporal motion-sensitive areas, MT+, peaked at 120 ms, followed by peaks in activity in the more dorsal area, V3A, at 160 ms and the lateral occipital complex at 180 ms. Approximately 250 ms after stimulus onset, activity fast motion stimuli was predominant in area V6 along the parieto-occipital sulcus. Finally, at 350 ms (100 ms after the motion offset) brain activity was visible again in area V1. For fast motion stimuli, the spatio-temporal brain pattern was similar, except that the first activity was detected at 70 ms in area MT+. Comparing functional magnetic resonance data for slow vs. fast motion, we found signs of slow-fast motion stimulus topography along the posterior brain in at least three cortical regions (MT+, V3A and LOR)

A systematic review on the interaction between emotion and pseudoneglect

Background: A large body of research has shown brain asymmetries in spatial attention. Specifically, there is an attention-processing advantage for the left visual field in healthy, right-handed subjects, known as “pseudoneglect.” Several studies have revealed that emotions modulate this basic spatial phenomenon, but the direction of the effect is still unclear. Here we systematically review empirical evidence on the behavioral effects of emotion on pseudoneglect. Methods: We searched through Pubmed, Scopus, PsycINFO, and PsychArticles. Original peer-reviewed articles published until February 2021 were included if they (1) were written in English; (2) were conducted on adults; (3) included at least one task to measure pseudoneglect, and (4) included at least one task with emotional stimuli or employed a measure of emotional state/trait, as they relate to pseudoneglect. Results: Fifteen studies were included, and 784 healthy participants took part in all studies reviewed. Discussion: The results show some evidence of emotion modulation of pseudoneglect, but evidence on the direction of the effect is mixed. We discuss the role of methodological factors that could account for the available findings and the implications for emotion asymmetry hypotheses such as the right-hemisphere hypothesis, the valence-specific hypothesis, as well as neural and arousal frameworks of attention–emotion interactions

Empirical evidence for intraspecific multiple realization?

Despite the remarkable advances in behavioral and brain sciences over the last decades, the mind-body (brain) problem is still an open debate and one of the most intriguing questions for both cognitive neuroscience and philosophy of mind. Traditional approaches have conceived this problem in terms of a contrast between physicalist monism and Cartesian dualism. However, since the late sixties, the landscape of philosophical views on the problem has become more varied and complex. The Multiple Realization Thesis (MRT) claims that mental properties can be (or are) realized, and mental processes can be (or are) implemented by neural correlates of different kinds. Thus, MRT challenges the psychoneural type-identity theory and the corresponding reductionism. Many philosophers have acknowledged the a priori plausibility of MRT. However, the existence of empirical evidence in favor of intraspecific, human multiple realizations of mental processes and properties is still controversial. Here, we illustrate some cases that provide empirical evidence in support of MRT. Recently, it has been proposed that foveal agnosic vision, like peripheral vision, can be restored by increasing object parts’ spacing (Crutch and Warrington, 2007; Strappini et al., 2017b). Agnosic fovea and normal periphery are both limited by crowding, which impairs object recognition, and provides the signature of visual integration. Here, we define a psychological property of restored object identification, and we cross-reference the data of visually impaired patients with different etiologies. In particular, we compare the data of two stroke patients, two patients with posterior cortical atrophy, six cases of strabismic amblyopia, and one case with restored sight. We also compare these patients with unimpaired subjects tested in the periphery. We show that integration (i.e., restored recognition) seems to describe quite accurately the visual performance in all these cases. Whereas the patients have different etiologies and different neural correlates, the unimpaired subjects have no neural damage. Thus, similarity in the psychological property given the differences in the neural substrate can be interpreted in relation to MRT and provide evidence in its support. Finally, we will frame our contribution within the current debate concerning MRT providing new and compelling empirical evidence

Detailed spatiotemporal brain mapping of chromatic vision combining high-resolution VEP with fMRI and retinotopy

Neuroimaging studies have identified so far, several color-sensitive visual areas in the human brain, and the temporal dynamics of these activities have been separately investigated using the visual-evoked potentials (VEPs). In the present study, we combined electrophysiological and neuroimaging methods to determine a detailed spatiotemporal profile of chromatic VEP and to localize its neural generators. The accuracy of the present co-registration study was obtained by combining standard fMRI data with retinotopic and motion mapping data at the individual level. We found a sequence of occipito activities more complex than that typically reported for chromatic VEPs, including feed-forward and reentrant feedback. Results showed that chromatic human perception arises by the combined activity of at the least five parieto-occipital areas including V1, LOC, V8/VO, and the motion-sensitive dorsal region MT+. However, the contribution of V1 and V8/VO seems dominant because the re-entrant activity in these areas was present more than once (twice in V8/VO and thrice in V1). This feedforward and feedback chromatic processing appears delayed compared with the luminance processing. Associating VEPs and neuroimaging measures, we showed for the first time a complex spatiotemporal pattern of activity, confirming that chromatic stimuli produce intricate interactions of many different brain dorsal and ventral areas

Spatio-temporal brain mapping of motion-onset VEPs combined with fMRI and retinotopic maps

Neuroimaging studies have identified several motion-sensitive visual areas in the human brain, but the time course of their activation cannot be measured with these techniques. In the present study, we combined electrophysiological and neuroimaging methods (including retinotopic brain mapping) to determine the spatio-temporal profile of motion-onset visual evoked potentials for slow and fast motion stimuli and to localize its neural generators. We found that cortical activity initiates in the primary visual area (V1) for slow stimuli, peaking 100 ms after the onset of motion. Subsequently, activity in the mid-temporal motion-sensitive areas, MT+, peaked at 120 ms, followed by peaks in activity in the more dorsal area, V3A, at 160 ms and the lateral occipital complex at 180 ms. Approximately 250 ms after stimulus onset, activity fast motion stimuli was predominant in area V6 along the parieto-occipital sulcus. Finally, at 350 ms (100 ms after the motion offset) brain activity was visible again in area V1. For fast motion stimuli, the spatio-temporal brain pattern was similar, except that the first activity was detected at 70 ms in area MT+. Comparing functional magnetic resonance data for slow vs. fast motion, we found signs of slow-fast motion stimulus topography along the posterior brain in at least three cortical regions (MT+, V3A and LOR). © 2012 Pitzalis et al

Spontaneously emerging patterns in human visual cortex reflect responses to naturalistic sensory stimuli

In the absence of stimulus or task, the cortex spontaneously generates rich and consistent functional connectivity patterns (termed resting state networks) which are evident even within individual cortical areas. We and others have previously hypothesized that habitual cortical network activations during daily life contribute to the shaping of these connectivity patterns. Here we tested this hypothesis by comparing, using blood oxygen level-dependent-functional magnetic resonance imaging, the connectivity patterns that spontaneously emerge during rest in retinotopic visual areas to the patterns generated by naturalistic visual stimuli (repeated movie segments). These were then compared with connectivity patterns produced by more standard retinotopic mapping stimuli (polar and eccentricity mapping). Our results reveal that the movie-driven patterns were significantly more similar to the spontaneously emerging patterns, compared with the connectivity patterns of either eccentricity or polar mapping stimuli. Intentional visual imagery of naturalistic stimuli was unlikely to underlie these results, since they were duplicated when participants were engaged in an auditory task. Our results suggest that the connectivity patterns that appear during rest better reflect naturalistic activations rather than controlled, artificially designed stimuli. The results are compatible with the hypothesis that the spontaneous connectivity patterns in human retinotopic areas reflect the statistics of cortical coactivations during natural vision

Neurophysiological mechanisms of mother–young bonding in buffalo and other farm animals

In buffaloes and other mammalian farm species, the mother provides food and protection to the young, but she is also the main source of behavioral and social learning for the offspring. It is important that mother and young establish a bond based on a learning mechanism defined as “imprinting” early after parturition during the sensitive period, on which the welfare and survival of the offspring will depend. This review aims to summarize and discuss current knowledge regarding the imprinting process, the neurobiological pathways that are triggered during this sensitive period, and the development of the cow–calf bond. Touch, hearing, vision, and smell seem to be the predominant senses involved during imprinting in buffaloes and other mammalian farm species. In buffalo, bonding is very particular due to the expression of specific behaviors, such as allo-suckling and communal rearing. In general, imprinting and the subsequent bond may be affected by the lack of experience of the mothers or dystocic parturitions, which occur most frequently with male calves and in primiparous dams. The main problems in the development of this process include lack of seeking a protected and isolated place to give birth; moving from the birth-site after parturition; insufficient postpartum care; aversion or aggressiveness towards the newborn, or abandonment of the newborn. The process can develop differently according to the species. However, the correct development of the cow–calf relationship represents, regardless of the species, a key factor for their fitness