Top-down Attentional Modulation Research Articles

Performing a Motor Action Enhances Social Reward Processing and Modulates the Neural Processing of Predictive Cues.

Associative learning affects many areas of human behavior. Recently, we showed that the neural response to monetary reward is enhanced by performing an action, suggesting interactions between neural systems controlling motor behavior and reward processing. Given many psychiatric disorders are associated with social anhedonia, a key open question is whether such effects generalize to social rewards, and in how far they affect associative learning. We developed a novel task in which participants (n = 66) received social reward feedback and social punishment either by pressing a button or waiting. Predictive cues were linked to feedback valence with 80% accuracy. Using EEG, we measured the neural response to both predictive cues and social feedback. We found enhanced reward positivity for social reward preceded by an action, and an enhanced N2 for cues predicting negative feedback. Cue-locked P3 amplitude was reduced for cues associated with negative feedback in passive trials only, showing a modulation of outcome anticipation by performing a motor action. This was supported by connectivity analyses showing stronger directed theta synchronization, in line with increased top-down modulation of attention, in active compared with passive trials. These findings suggest that actively obtaining social feedback enhances reward sensitivity and modulates outcome anticipation.

Category-based attention facilitates memory search.

We often need to decide whether the object we look at is also the object we look for. When we look for one specific object, this process can be facilitated by feature-based attention. However, when we look for many objects at the same time (e.g., the products on our shopping list) such a strategy may no longer be possible, as research has shown that we can actively prepare to detect only one or two objects at a time. Therefore, looking for multiple objects additionally requires long-term memory search, slowing down decision making. Interestingly, however, previous research has shown that distractor objects can be efficiently rejected during memory search when they are from a different category than the items in the memory set. Here, using EEG, we show that this efficiency is supported by top-down attention at the category level. In Experiment 1, human participants (both sexes) performed a memory search task on individually presented objects from different categories, most of which were distractors. We observed category-level attentional modulation of distractor processing from ∼150 ms after stimulus onset, expressed both as an evoked response modulation and as an increase in decoding accuracy of same-category distractors. In Experiment 2, memory search was performed on two concurrently presented objects. When both objects were distractors, spatial attention (indexed by the N2pc component) was directed to the object that was of the same category as the objects in the memory set. Together, these results demonstrate how top-down attention can facilitate memory search.Significance statement When we are in the supermarket, we repeatedly decide whether a product we look at (e.g., a banana) is on our memorized shopping list (e.g., apples, oranges, kiwis). This requires searching our memory, which takes time. However, when the product is of an entirely different category (e.g., dairy instead of fruit), the decision can be made quickly. Here, we used EEG to show that this between-category advantage in memory search tasks is supported by top-down attentional modulation of visual processing: The visual response evoked by distractor objects was modulated by category membership, and spatial attention was quickly directed to the location of within-category (vs. between-category) distractors. These results demonstrate a close link between attention and memory.

Pathway-selective optogenetics reveals the functional anatomy of top-down attentional modulation in the macaque visual cortex.

Spatial attention represents a powerful top-down influence on sensory responses in primate visual cortical areas. The frontal eye field (FEF) has emerged as a key candidate area for the source of this modulation. However, it is unclear whether the FEF exerts its effects via its direct axonal projections to visual areas or indirectly through other brain areas and whether the FEF affects both the enhancement of attended and the suppression of unattended sensory responses. We used pathway-selective optogenetics in rhesus macaques performing a spatial attention task to inhibit the direct input from the FEF to area MT, an area along the dorsal visual pathway specialized for the processing of visual motion information. Our results show that the optogenetic inhibition of the FEF input specifically reduces attentional modulation in MT by about a third without affecting the neurons' sensory response component. We find that the direct FEF-to-MT pathway contributes to both the enhanced processing of target stimuli and the suppression of distractors. The FEF, thus, selectively modulates firing rates in visual area MT, and it does so via its direct axonal projections.

Neural signatures of hierarchical linguistic structures in second language listening comprehension.

Native speakers excel at parsing continuous speech into smaller elements and entraining their neural activities to the linguistic hierarchy at different levels (e.g., syllables, phrases and sentences) to achieve speech comprehension. However, how a nonnative brain tracks hierarchical linguistic structures in second language (L2) speech comprehension and whether it relates to top-down attention and language proficiency remains elusive. Here, we applied a frequency-tagging paradigm in human adults and investigated the neural tracking responses to hierarchically organized linguistic structures (i.e., the syllabic rate of 4 Hz, the phrasal rate of 2 Hz and the sentential rate of 1 Hz) in both first language (L1) and L2 listeners when they attended to a speech stream or ignored it. We revealed disrupted neural responses to higher-order linguistic structures (i.e., phrases and sentences) for L2 listeners in which the phrasal-level tracking was functionally related to an L2 subject's language proficiency. We also observed less efficient top-down modulation of attention in L2 speech comprehension than in L1 speech comprehension. Our results indicate that the reduced delta-band neuronal oscillations that subserve the internal construction of higher-order linguistic structures may compromise listening comprehension in a nonnative language.Significance statementLow-frequency neural oscillations are at the root of speech comprehension in a native brain. How a nonnative brain tracks hierarchical linguistic structures in L2 speech and whether it relates to attention and language proficiency has not been established. Our study recorded electrophysiological responses to the linguistic structures at the syllabic, the phrasal and the sentential rates for L2 listeners and found reduced tracking responses to the higher-order linguistic structures in L2 compared to L1, which relates to L2 proficiency at the behavioral level. Moreover, unlike native listeners, who automatically tracked speech structures without attention, nonnative listeners could not track higher-order linguistic structures in L2 speech during passive listening, indicating a different pattern of attentional modulation in a nonnative brain.

A brain-inspired object-based attention network for multiobject recognition and visual reasoning.

The visual system uses sequences of selective glimpses to objects to support goal-directed behavior, but how is this attention control learned? Here we present an encoder-decoder model inspired by the interacting bottom-up and top-down visual pathways making up the recognition-attention system in the brain. At every iteration, a new glimpse is taken from the image and is processed through the "what" encoder, a hierarchy of feedforward, recurrent, and capsule layers, to obtain an object-centric (object-file) representation. This representation feeds to the "where" decoder, where the evolving recurrent representation provides top-down attentional modulation to plan subsequent glimpses and impact routing in the encoder. We demonstrate how the attention mechanism significantly improves the accuracy of classifying highly overlapping digits. In a visual reasoning task requiring comparison of two objects, our model achieves near-perfect accuracy and significantly outperforms larger models in generalizing to unseen stimuli. Our work demonstrates the benefits of object-based attention mechanisms taking sequential glimpses of objects.

Top-down modulation of visual cortical processing after transient congenital blindness

Early visual experience has been shown to be critical for the development of visual and multisensory functions; however, its impact on functional brain organization remains largely unexplored. Here, we therefore investigated the effect of early visual deprivation on top-down attentional modulation of visual cortical processing within the occipito-temporal cortex. Furthermore, we explored whether early visual deprivation may affect the extent to which typically visual, motion-selective area hMT responds to moving visual stimuli. Using functional magnetic resonance imaging, we compared cortical responses in area hMT and in the fusiform face area (FFA) to moving face stimuli – which were either task relevant or task irrelevant – relative to stationary face stimuli between cataract-reversal participants and normally sighted controls. Although both groups exhibited significantly stronger visual cortical responses in area hMT to moving stimuli than during the stationary baseline, the magnitude of this effect was significantly lower in the cataract-reversal group. In contrast, both groups exhibited significantly enhanced visual cortical responses in area hMT and in the FFA when moving face stimuli were task relevant compared to when they were task irrelevant, with no significant differences between groups in the magnitude of these effects. These results indicate that top-down attentional modulation of visual cortical processing in area hMT and FFA does not depend on early visual experience. Furthermore, the present results suggest that the functional specialization of area hMT for visual motion processing may be partially disrupted by early visual deprivation.

Alpha oscillatory activity during attentional control in children with Autism Spectrum Disorder (ASD), Attention-Deficit/Hyperactivity Disorder (ADHD), and ASD+ADHD.

Autism Spectrum Disorder (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD) share impairments in top-down and bottom-up modulation of attention. However, it is not yet well understood if co-occurrence of ASD and ADHD reflects a distinct or additive profile of attention deficits. We aimed to characterise alpha oscillatory activity (stimulus-locked alpha desynchronisation and prestimulus alpha) as an index of integration of top-down and bottom-up attentional processes in ASD and ADHD. Children with ASD, ADHD, comorbid ASD+ADHD, and typically-developing children completed a fixed-choice reaction-time task ('Fast task') while neurophysiological activity was recorded. Outcome measures were derived from source-decomposed neurophysiological data. Main measures of interest were prestimulus alpha power and alpha desynchronisation (difference between poststimulus and prestimulus alpha). Poststimulus activity linked to attention allocation (P1, P3), attentional control (N2), and cognitive control (theta synchronisation, 100-600 ms) was also examined. ANOVA was used to test differences across diagnostics groups on these measures. Spearman's correlations were used to investigate the relationship between attentional control processes (alpha oscillations), central executive functions (theta synchronisation), early visual processing (P1), and behavioural performance. Children with ADHD (ADHD and ASD+ADHD) showed attenuated alpha desynchronisation, indicating poor integration of top-down and bottom-up attentional processes. Children with ADHD showed reduced N2 and P3 amplitudes, while children with ASD (ASD and ASD+ADHD) showed greater N2 amplitude, indicating atypical attentional control and attention allocation across ASD and ADHD. In the ASD group, prestimulus alpha and theta synchronisation were negatively correlated, and alpha desynchronisation and theta synchronisation were positively correlated, suggesting an atypical association between attentional control processes and executive functions. ASD and ADHD are associated with disorder-specific impairments, while children with ASD+ADHD overall presented an additive profile with attentional deficits of both disorders. Importantly, these findings may inform the improvement of transdiagnostic procedures and optimisation of personalised intervention approaches.

Standing out in a small crowd: The role of display size in attracting attention

ABSTRACT Strong evidence supporting the top-down modulation of attention has come from studies in which participants learned to suppress a singleton in a heterogeneous four-item display. These studies have been criticized on the grounds that the displays are so sparse that the singleton is not actually salient. We argue that similar evidence of suppression has been found with substantially larger displays where salience is not in question. Additionally, we examine the results of applying salience models to four-item displays, and find prominent markers of salience at the location of the singleton. We conclude that small heterogeneous displays do not preclude strong salience signals. Beyond that, we reflect on how further basic research on salience may speed resolution of the attentional capture debate.

Computational animal welfare: towards cognitive architecture models of animal sentience, emotion and wellbeing.

To understand animal wellbeing, we need to consider subjective phenomena and sentience. This is challenging, since these properties are private and cannot be observed directly. Certain motivations, emotions and related internal states can be inferred in animals through experiments that involve choice, learning, generalization and decision-making. Yet, even though there is significant progress in elucidating the neurobiology of human consciousness, animal consciousness is still a mystery. We propose that computational animal welfare science emerges at the intersection of animal behaviour, welfare and computational cognition. By using ideas from cognitive science, we develop a functional and generic definition of subjective phenomena as any process or state of the organism that exists from the first-person perspective and cannot be isolated from the animal subject. We then outline a general cognitive architecture to model simple forms of subjective processes and sentience. This includes evolutionary adaptation which contains top-down attention modulation, predictive processing and subjective simulation by re-entrant (recursive) computations. Thereafter, we show how this approach uses major characteristics of the subjective experience: elementary self-awareness, global workspace and qualia with unity and continuity. This provides a formal framework for process-based modelling of animal needs, subjective states, sentience and wellbeing.

Modulation of anticipatory visuospatial attention in sustained and transient tasks

The anticipation of upcoming events is a key-feature of cognition. Previous investigations on anticipatory visuospatial attention mainly adopted transient and–more rarely–sustained tasks, whose main difference consists in the presence of transient or sustained cue stimuli and different involvement of top-down or bottom-up forms of attention. In particular, while top-down control has been suggested to drive sustained attention, it is not clear whether both endogenous and exogenous controls are recruited in transient attention task, or whether the cue-evoked attention may be interpreted as a mainly bottom-up guided process. To solve this issue, the present study focused on the preparatory brain activity of participants performing a sustained and a transient attention task. To this aim, the focus was on pre-stimulus event-related potential (ERP) components, i.e., the prefrontal negativity (pN) and the visual negativity (vN), associated with cognitive and sensorial preparation, emerging from prefrontal and visual areas, respectively. Results indicated that the pN was specific for the sustained task, while the vN emerged for both tasks, although smaller in the transient task, with a hemispheric lateralization contralateral to the attended hemifield. The present findings support the interpretation of the vN as a modality-specific index of attentional preparation, and suggest the presence of cognitive endogenous control in sustained tasks only, as revealed by the presence of a prefrontal activity that was interpreted as the locus of the top-down attentional modulation during the stimulus expectancy stage.

Abnormal functional connectivity and effective connectivity between the default mode network and attention networks in patients with alcohol-use disorder.

Patients with alcohol-use disorder (AUD) demonstrate dysfunctional cerebral network connectivity. However, limited studies have investigated attention systems in AUD. To assess functional (FC) and effective connectivity (EC) in the dorsal (DAN) and ventral attention networks (VAN) and default mode network (DMN) in patients with AUD using resting-state functional magnetic resonance imaging (rs-fMRI). MRI and rs-fMRI data were obtained from 28 men with AUD and 30 age-matched healthy controls. Independent component analysis was used to identify and extract network data, for comparison between the two groups. Effective connectivity was evaluated using Granger causality analysis (GCA) by selecting significantly different brain areas as regions of interest (ROI). Signed-path coefficients between ROIs were computed in bivariate mode. In patients with AUD, FC decreased in the left superior parietal gurus (SPG) and left interparietal sulcus (IPS, in DAN); FC decreased in the right superior frontal gyrus (SPG) and right middle frontal gyrus (MFG, in DMN). GCA values indicated that the DMN exerts a positive causal effect on the DAN (P = 0.007/0.027), which consequently exerts a negative causal effect on the DMN (P = 0.032). Signed-path coefficients from the right MFG to the left IPS correlated negatively with MAST scores (P = 0.015). We found novel inter-network connectivity dysfunction in patients with AUD, which indicates abnormal causal relations between resting-state DAN and DMN. Thus, patients with AUD may have abnormal top-down attention modulation and cognition.

Spatiotemporal dynamics of working memory under the influence of emotions based on EEG

Objective. Previous studies have reported that working memory (WM) may be affected by emotions and that the effect may exist in different stages of WM. However, at present it remains controversial whether emotions inhibit or facilitate WM, and how the mechanism of dynamic information transmission in the brain during WM is affected by emotions. Approach. In this study, we used a video database to induce three emotions (negative, neutral, and positive) and adopted a change detection paradigm based on electroencephalography. Event-related potential (ERP) analysis, event-related spectral perturbation analysis, source location analysis based on the dipole localization method and the distributed source localization method, and effective connectivity analysis were performed. Main results. Both behavioral and ERP results suggest that positive emotions have no significant effect on WM capacity, while negative emotions could facilitate WM capacity. Furthermore, the effective connectivity results based on two source location methods suggest that the long-range connectivity between the frontal and posterior areas can reflect the influence of positive and negative emotions on the WM network, in which the connectivity under the positive emotion condition occurs in the earlier period of WM maintenance, while the connectivity under the negative emotion condition occurs in the later period of WM maintenance. Significance. The consistency of the behavioral, ERP, and effective connectivity results suggests that under the negative emotion condition, the top-down attention modulation between the frontoparietal area and posterior area could promote the most relevant information storage during WM maintenance.

Improving sentence reading performance in Chinese children with developmental dyslexia by training based on visual attention span

Deficits in the visual attention span (VAS) are thought to hamper reading performance in dyslexic individuals. However, the causal relationship between VAS deficits and reading disability remains unclear. The present study attempts to address this issue by using a VAS-based intervention to explore the possible influence of VAS on reading processes in Chinese children with dyslexia. Given the influence of the heterogeneity of dyslexia on intervention effects, VAS-impaired dyslexic and VAS-intact dyslexic individuals were separately trained. Therefore, there were five groups of participants in this study, including 10 trained dyslexic individuals with VAS deficits and 10 untrained dyslexic individuals with VAS dysfunction as the baseline reference, 10 trained and 10 untrained dyslexic individuals with an intact VAS, and fourteen age-matched normal readers for reference of normal level. All participants completed reading measures and a visual 1-back task, reflecting VAS capacity with non-verbal stimuli and non-verbal responses, before and after VAS-based training. VAS-based training tasks included a length estimation task regarding the bottom-up attention, visual search and digit cancelling tasks targeting top-down attentional modulation, and visual tracking tasks to train eye-movement control. The results showed that visual training only helped improve VAS skills in VAS-impaired dyslexic individuals receiving training. Meanwhile, their silent sentence reading accuracy improved after training, and there was a significant relationship between training improvements in VAS function and reading performance. The current findings suggest that VAS-based training has a far-transfer effect on linguistic level (i.e., fluent reading). These findings suggest the possibility that VAS-related training may help children with dyslexia improve their reading skills.

Prefrontal theta modulates sensorimotor gamma networks during the reorienting of attention

The ability to execute a motor plan involves spatiotemporally precise oscillatory activity in primary motor (M1) regions, in concert with recruitment of “higher order” attentional mechanisms for orienting toward current task goals. While current evidence implicates gamma oscillatory activity in M1 as central to the execution of a movement, far less is known about top‐down attentional modulation of this response. Herein, we utilized magnetoencephalography (MEG) during a Posner attention‐reorienting task to investigate top‐down modulation of M1 gamma responses by frontal attention networks in 63 healthy adult participants. MEG data were evaluated in the time–frequency domain and significant oscillatory responses were imaged using a beamformer. Robust increases in theta activity were found in bilateral inferior frontal gyri (IFG), with significantly stronger responses evident in trials that required attentional reorienting relative to those that did not. Additionally, strong gamma oscillations (60–80 Hz) were detected in M1 during movement execution, with similar responses elicited irrespective of attentional reorienting. Whole‐brain voxel‐wise correlations between validity difference scores (i.e., attention reorienting trials—nonreorienting trials) in frontal theta activity and movement‐locked gamma oscillations revealed a robust relationship in the contralateral sensorimotor cortex, supplementary motor area, and right cerebellum, suggesting modulation of these sensorimotor network gamma responses by attentional reorienting. Importantly, the validity difference effect in this distributed motor network was predictive of overall motor function measured outside the scanner and further, based on a mediation analysis this relationship was fully mediated by the reallocation response in the right IFG. These data are the first to characterize the top‐down modulation of movement‐related gamma responses during attentional reorienting and movement execution.

Developmental Changes of Top-down Attentional Modulation in Saliency Model

Developmental Changes of Top-down Attentional Modulation in Saliency Model

Top-down attention modulation on the perception of others’ vocal pain: An event-related potential study

Pain is typically expressed through various sensory (e.g., visual and auditory) modalities: the human voice conveys information about social and affective communication. While the empathic responses to others' pain in the visual modality are modulated by top-down attention constraints, it remains unclear whether empathy for such expressions in the auditory modality also involves such top-down modulation mechanisms. Therefore, the present study investigates how neural correlates of empathic processes to others' vocal pain are modulated by the task-instructed attention manipulations. Each participant completed the following three tasks: (1) Pain Judgment Task, in which participants were instructed to pay attention to pain cues in vocal stimuli, (2) Gender Judgment Task, in which participants were instructed to pay attention to non-pain cues in vocal stimuli; (3) Passive Listening Task, a control task in which participants were instructed to passively listen to the vocal stimuli without any required response. The earlier frontal-central N1 response to either others' painful or neutral voice was greater in the Pain Judgment Task than in the other two tasks, suggesting a general attention modulation on the bottom-up sensory processing of vocal stimuli. The frontal-central P2 responses to others' painful voices was greater in the Pain Judgment Task than in the other two tasks, but not to others' neutral voices, thus suggesting selective attention modulation on the P2 response to others' pain. Late positive complex (LPC) to others' painful and neutral voices differed significantly regardless of task manipulations, thus suggesting empathic pain modulation on LPC response. All these results demonstrated top-down attention modulation on affective sharing responses others' vocal pain, but not on cognitive appraisal process of others’ vocal pain.

Evidence for early top-down modulation of attention to salient visual cues through probe detection.

The influence of top-down attentional control on the selection of salient visual stimuli has been examined extensively. Some accounts suggest all salient stimuli capture attention in a stimulus-driven manner, while others suggest salient stimuli capture attention contingent on top-down relevance. Evidence consistently shows target templates allow only salient stimuli sharing a target's features to capture attention, while salient stimuli not sharing a target's features do not. A number of hypotheses (e.g., contingent orienting, disengagement, signal suppression) from both sides of this debate have been proposed; however, most predict similar performance in the visual search and spatial cuing tasks. The present study combined a cuing task, in which subjects identified a target defined by its having a unique feature, with a probe identification task developed by Gaspelin, Leonard, and Luck (Psychological Science, 26, 1740-1750, 2015), in which subjects identified letters appearing in potential target locations just after the appearance of a salient cue that matched or did not match the target-defining feature. The probe task provided a measure of where attention was focused just after the cue's appearance. In six experiments, we observed top-down modulation of spatial cuing effects in response times and probe identification: Probes in the cued location were identified more often, but more when preceded by a cue that shared the target-defining feature. Though not unequivocal, the results are explained in terms of the on-going debate over whether top-down attentional control can prevent bottom-up capture by salient, task-irrelevant stimuli.

Development of spatial suppression surrounding the focus of visual attention.

In adulthood, research has demonstrated that surrounding the spatial location of attentional focus is a suppressive field, resulting from top-down attention promoting the processing of relevant stimuli and inhibiting surrounding distractors (e.g., Hopf et al., 2006). It is not fully known, however, how this phenomenon manifests during development. This is an important question since attention processes are likely even more critical in development because of their potential impact on learning and day-to-day activities. The current study examined whether spatial suppression surrounding the focus of visual attention, a predicted by-product of top-down attentional modulation, is observed in development. A wide age range separated in six incremental age levels was included, allowing for a detailed examination of potential differences in the effect of attention on visual processing across development. Participants between 12 and 27 years of age exhibited spatial suppression surrounding their focus of visual attention. Their accuracy increased as a function of the separation distance between a spatially cued (and attended) target and a second target, suggesting that a ring of suppression surrounded the attended target. Attentional surround suppression was not observed in 8- to 11-years-olds, even with a longer spatial cue presentation time, demonstrating that the lack of the effect at these ages is not due to slowed attentional feedback processes. Our findings demonstrate that top-down attentional processes exhibit functional maturity beginning around 12 years of age with continuing maturation of their expression until 17, which likely impacts education and the diagnosis of visual and cognitive clinical pathologies.

Top-down Effects on Empathy for Pain in Adults with Autistic Traits

While empathic responses of individuals with autism-spectrum disorder have been reported to be modulated by top-down attention, it remains unclear whether empathy for pain in typically developing individuals with autistic traits also involves such top-down modulation mechanisms. This study employed the autism-spectrum quotient (AQ) to quantify autistic traits in a group of 1,231 healthy adults. Two subset groups (High-AQ and Low-AQ groups) were randomly selected from the highest and lowest 10% AQ scores respectively. We explored whether participants in both groups would differ in their response to others’ pain when their attention was directed toward (A-P tasks) or away (A-N tasks) from pain cues in auditory and visual experimental modalities. Compared to Low-AQ individuals, High-AQ individuals exhibited more suppressed N1 and P2 amplitudes in response to painful vocal cues in auditory A-N tasks. This suggests suppressed attentional and emotional processes of empathy for pain when High-AQ individuals have their attention directed away from others’ pain cues. No significant difference was found between both groups in the auditory A-P task, nor in the visual A-P and A-N tasks. These results suggest that top-down attention modulation of cortical empathic responses to others’ vocal pain is influenced by autistic traits.

Electrophysiological correlates of top-down attentional modulation in olfaction

The capacity to pay attention is important for the cognitive ability, for example, evaluating an object for its qualities. Attention can selectively prioritize the neural processes that are relevant to a given task. Neuroimaging investigations on human attention are primarily focused on vision to the exclusion of other sensory systems, particularly olfaction. Neural underpinnings of human olfactory attention are still not clearly understood. Here, we combined electroencephalographic measurements of olfactory event related potential with electrical neuroimaging to investigate how the neural responses after inhaling the same odor differ between conditions with varying levels of attention, and, in which brain areas. We examined the neural responses when participants attended to a rose-like odor of phenylethyl alcohol for evaluating its pleasantness versus its passive inhalation. Our results gathered significant evidence for attentional modulation of the olfactory neural response. The most prominent effect was found for the late positive component, P3, of olfactory event related potential within a second from the odor onset. The source reconstruction of this data revealed activations in a distributed network of brain regions predominantly in inferior frontal cortex, insula, and inferior temporal gyrus. These results suggest that the neuronal modulations from attention to olfactory pleasantness may be subserved by this network.