Coexistence of Attention-Based Facilitation and Inhibition in the Human Cortex

Abstract

A key function of attention is to select an appropriate subset of available information by facilitation of attended processes and/or inhibition of irrelevant processing. Functional imaging studies, using positron emission tomography, have during different experimental tasks revealed decreased neuronal activity in areas that process input from unattended sensory modalities. It has been hypothesized that these decreases reflect a selective inhibitory modulation of nonrelevant cortical processing. In this study we addressed this question using a continuous arithmetical task with and without concomitant disturbing auditory input (task-irrelevant speech). During the arithmetical task, irrelevant speech did not affect task-performance but yielded decreased activity in the auditory and midcingulate cortices and increased activity in the left posterior parietal cortex. This pattern of modulation is consistent with a top down inhibitory modulation of a nonattended input to the auditory cortex and a coexisting, attention-based facilitation of taskrelevant processing in higher order cortices. These findings suggest that task-related decreases in cortical activity may be of functional importance in the understanding of both attentional mechanisms and taskrelated information processing. Academic Press

Region-specific uncoupling of oxygen and glucose metabolism in the human cortex during visual stimulation

“…Increases in CMRglc and CMRO₂ were largely confined to task-engaged regions, indicating that metabolic demand tracks local neuronal activity (Herman et al, 2025; Wolfe et al, 2024; Yu et al, 2018). Outside the visual cortex, by contrast, widespread CBF reductions were accompanied by decreases in CMRO₂ consistent with a supply-limited framework of brain metabolism (Herculano-Houzel & Rothman, 2022) and with prior reports of activation-related CBF redistribution and reduced oxygen metabolism (Bruckmaier et al, 2020; Ghatan et al, 1998; Kastner & Ungerleider, 2000). Together, these observations indicate that the BOLD response reflects a combination of localized neurometabolic activity and broader vascular dynamics rather than a direct readout of regional energy consumption, a distinction we have recently shown can even reverse the apparent sign of oxygen metabolism (Epp et al, 2026).…”

Region-specific uncoupling of oxygen and glucose metabolism in the human cortex during visual stimulation

“…Increases in CMRglc and CMRO₂ were largely confined to task-engaged regions, indicating that metabolic demand tracks local neuronal activity (Herman et al, 2025; Wolfe et al, 2024; Yu et al, 2018). Outside the visual cortex, by contrast, widespread CBF reductions were accompanied by decreases in CMRO₂ consistent with a supply-limited framework of brain metabolism (Herculano-Houzel & Rothman, 2022) and with prior reports of activation-related CBF redistribution and reduced oxygen metabolism (Bruckmaier et al, 2020; Ghatan et al, 1998; Kastner & Ungerleider, 2000). Together, these observations indicate that the BOLD response reflects a combination of localized neurometabolic activity and broader vascular dynamics rather than a direct readout of regional energy consumption, a distinction we have recently shown can even reverse the apparent sign of oxygen metabolism (Epp et al, 2026).…”

Effects of Selective Attention on the Electrophysiological Representation of Concurrent Sounds in the Human Auditory Cortex

“…9B), selective attention seems to mainly operate by reducing the neural encoding of the irrelevant sounds (21 Hz SSR in the AS29 condition; and transient responses to 29 Hz stream onset and 29 Hz SSR in the AS21 condition) from 150 ms after stimulus onset. This reduction of irrelevant information processing is consistent with previous electrophysiological (Alho et al, 1987(Alho et al, , 1994Donald, 1987;Michie et al, 1990Michie et al, , 1993Alain and Woods, 1994), PET (Ghatan et al, 1998;Kawashima et al, 1999) and lesion (Knight et al, 1989) studies on auditory selective attention. As shown previ-ously (Donald, 1987;Michie et al, 1990Michie et al, , 1993, this reduction occurred later in the sensory processing chain than the attentional enhancement.…”

The irrelevant speech effect: a PET study

“…Taken together, the reported activations and areas of decreased activity can be interpreted in terms of suppression of irrelevant areas consistent with previous findings (Ghatan et al, 1998). Decreases of activation were found in the bilateral (left > right) superior temporal region, the bilateral inferior/middle frontal cortices (right > left), as well as in the left inferior parietal cortex (Fig.…”

Region-specific uncoupling of oxygen and glucose metabolism in the human cortex during visual stimulation

“…Increases in CMRglc and CMRO₂ were largely confined to task-engaged regions, indicating that metabolic demand tracks local neuronal activity (Herman et al, 2025; Wolfe et al, 2024; Yu et al, 2018). Outside the visual cortex, by contrast, widespread CBF reductions were accompanied by decreases in CMRO₂ consistent with a supply-limited framework of brain metabolism (Herculano-Houzel & Rothman, 2022) and with prior reports of activation-related CBF redistribution and reduced oxygen metabolism (Bruckmaier et al, 2020; Ghatan et al, 1998; Kastner & Ungerleider, 2000). Together, these observations indicate that the BOLD response reflects a combination of localized neurometabolic activity and broader vascular dynamics rather than a direct readout of regional energy consumption, a distinction we have recently shown can even reverse the apparent sign of oxygen metabolism (Epp et al, 2026).…”

Effects of Selective Attention on the Electrophysiological Representation of Concurrent Sounds in the Human Auditory Cortex

“…9B), selective attention seems to mainly operate by reducing the neural encoding of the irrelevant sounds (21 Hz SSR in the AS29 condition; and transient responses to 29 Hz stream onset and 29 Hz SSR in the AS21 condition) from 150 ms after stimulus onset. This reduction of irrelevant information processing is consistent with previous electrophysiological (Alho et al, 1987(Alho et al, , 1994Donald, 1987;Michie et al, 1990Michie et al, , 1993Alain and Woods, 1994), PET (Ghatan et al, 1998;Kawashima et al, 1999) and lesion (Knight et al, 1989) studies on auditory selective attention. As shown previ-ously (Donald, 1987;Michie et al, 1990Michie et al, , 1993, this reduction occurred later in the sensory processing chain than the attentional enhancement.…”

The irrelevant speech effect: a PET study

“…Taken together, the reported activations and areas of decreased activity can be interpreted in terms of suppression of irrelevant areas consistent with previous findings (Ghatan et al, 1998). Decreases of activation were found in the bilateral (left > right) superior temporal region, the bilateral inferior/middle frontal cortices (right > left), as well as in the left inferior parietal cortex (Fig.…”

Region-specific uncoupling of oxygen and glucose metabolism in the human cortex during visual stimulation

“…Increases in CMRglc and CMRO₂ were largely confined to task-engaged regions, indicating that metabolic demand tracks local neuronal activity (Herman et al, 2025; Wolfe et al, 2024; Yu et al, 2018). Outside the visual cortex, by contrast, widespread CBF reductions were accompanied by decreases in CMRO₂ consistent with a supply-limited framework of brain metabolism (Herculano-Houzel & Rothman, 2022) and with prior reports of activation-related CBF redistribution and reduced oxygen metabolism (Bruckmaier et al, 2020; Ghatan et al, 1998; Kastner & Ungerleider, 2000). Together, these observations indicate that the BOLD response reflects a combination of localized neurometabolic activity and broader vascular dynamics rather than a direct readout of regional energy consumption, a distinction we have recently shown can even reverse the apparent sign of oxygen metabolism (Epp et al, 2026).…”

Effects of Selective Attention on the Electrophysiological Representation of Concurrent Sounds in the Human Auditory Cortex

“…9B), selective attention seems to mainly operate by reducing the neural encoding of the irrelevant sounds (21 Hz SSR in the AS29 condition; and transient responses to 29 Hz stream onset and 29 Hz SSR in the AS21 condition) from 150 ms after stimulus onset. This reduction of irrelevant information processing is consistent with previous electrophysiological (Alho et al, 1987(Alho et al, , 1994Donald, 1987;Michie et al, 1990Michie et al, , 1993Alain and Woods, 1994), PET (Ghatan et al, 1998;Kawashima et al, 1999) and lesion (Knight et al, 1989) studies on auditory selective attention. As shown previ-ously (Donald, 1987;Michie et al, 1990Michie et al, , 1993, this reduction occurred later in the sensory processing chain than the attentional enhancement.…”

The irrelevant speech effect: a PET study

“…Taken together, the reported activations and areas of decreased activity can be interpreted in terms of suppression of irrelevant areas consistent with previous findings (Ghatan et al, 1998). Decreases of activation were found in the bilateral (left > right) superior temporal region, the bilateral inferior/middle frontal cortices (right > left), as well as in the left inferior parietal cortex (Fig.…”