The research, conducted by a team at the University of Maastricht and presented at the annual congress of the European College of Neuropsychopharmacology (ECNP) in Munich, examined how microdosed LSD influenced three domains of mental performance: sustained attention, information processing speed, and working memory. In a randomised, double-blind, placebo-controlled design, 48 healthy volunteers, 24 women and 24 men with an average age of 36.9 years, were assigned to receive either an inert placebo or four doses of LSD over a two-week period. Each dose contained 15 micrograms, a quantity well below the threshold at which the characteristic psychedelic effects of LSD typically appear, which the researchers note generally requires more than 60 micrograms. Neither participants nor investigators knew who had received the active drug until the entire study had been completed, a design feature that helps guard against expectation effects, which are known to be particularly powerful in psychedelic research.

Participants were tested on four occasions: at the start of the study, after the first dose, after the fourth and final dose, and again at a follow-up session. Across the battery of tasks, one result stood out clearly. In a test of sustained attention, in which participants had to watch a screen and respond as quickly as possible whenever a signal appeared, the women who received LSD performed markedly better than the women who received placebo. Their reactions to the visual stimulus were about 8 percent faster, averaging 308 milliseconds under LSD compared with 335 milliseconds under placebo. Perhaps more strikingly, the treated women committed an average of 2.3 lapses in attention, a common laboratory measure of momentary losses in focus, while women in the placebo group averaged 4.7 lapses, roughly twice as many.

Crucially, this improvement in sustained attention was not a one-off observation confined to a single testing session. The advantage for the LSD group on attentional lapses appeared after the very first dose, persisted after repeated dosing across the two-week period, and could still be detected at follow-up. In contrast, the men in the study showed no comparable benefit. Their performance on the sustained attention task under microdosed LSD was not meaningfully different from their performance under placebo. The dissociation between the sexes was the most notable finding of the study, and it suggests that pooled analyses, which collapse results across men and women, may obscure real effects that apply only to a subset of participants.

Lead researcher Iva Totomanova of the University of Maastricht emphasized that the finding must be interpreted with care. She explained that the team examined the effect of LSD on three different cognitive tasks, and that the clearest result concerned how women sustain attention. For the information processing and working memory tasks, she noted, the results were not as clear-cut, which may help explain why sex-related effects have been missed in previous studies. She was careful to state that the work does not show that low-dose LSD generally improves cognition, nor that women are generally more responsive to LSD than men. Instead, she said, the results point to a more cautious message: effects may depend on the person, the specific cognitive task being measured, and the circumstances of use. In her view, a better research question may be who responds to microdosing, and under what conditions.

The study is, importantly, a re-analysis of data from an earlier completed trial rather than an experiment designed from the outset to probe sex differences. The authors acknowledge this limitation openly. They note that confirming the finding will require research specifically built to examine how sex shapes the response to psychedelics, for example by measuring hormone concentrations in the blood and accounting for menstrual phase and the use of hormonal contraceptives. Such factors, which vary systematically over time and between individuals, could plausibly interact with serotonergic drugs like LSD and may help explain why men and women responded differently in this dataset.

The biological rationale for such a sex difference remains an open question, but it is not implausible. LSD acts primarily on serotonin receptors, particularly the 5-HT2A subtype, and serotonergic signalling is known to interact with ovarian hormones such as estrogen, which themselves modulate attention and cognitive performance. Differences in hormone state, drug metabolism, or baseline attentional profiles could all contribute to a scenario in which women show measurable gains while men do not. The finding that women given placebo tended to have slower reaction times and more attention lapses than men on the same task also suggests that the two groups started from different baselines, leaving more room for improvement among the women.

The broader context for this work is a field marked by conflicting results. Observational surveys of people who microdose on their own have often reported striking benefits for focus and mood, but such self-selected samples are vulnerable to expectation effects. Laboratory-based placebo-controlled trials, by contrast, have frequently found that improvements occur in both the active drug and placebo groups, suggesting that much of the perceived benefit of microdosing may be driven by belief rather than pharmacology. The Maastricht study is notable because the participants did not know whether they had received LSD or placebo, and because a genuine drug-by-sex interaction emerged despite the small sample. Totomanova observed that researchers are beginning to see that people respond to psychedelics in different ways, and that with psychedelic pharmaceuticals, personalised medicine looks likely to be important.

Independent experts reacted to the findings with measured interest. Dr Mikkel Højlund of the University of Southern Denmark, who was not involved in the work, commented that microdosing of psychedelics has received a great deal of media attention, so testing it in a proper research context is important for advancing knowledge on the subject. He noted that even though the study was double-blind and placebo-controlled, the researchers themselves are cautious, describing it as a small study with several variables, but one that merits further work on a bigger scale. His assessment echoes the authors’ own framing: the result is promising and scientifically interesting, but it is a signal from a pilot dataset rather than a definitive demonstration.

As interest in psychedelic therapeutics continues to grow, studies of this kind underscore a central lesson of modern psychopharmacology: average effects across a mixed population can hide effects that are real and substantial for particular groups. The Maastricht team’s data suggest that low-dose LSD may meaningfully enhance sustained attention in women, roughly halving attentional lapses and speeding responses by about 8 percent, while leaving men untouched on the same measure. If future trials designed specifically to test sex differences confirm the pattern, and if the mechanisms behind it can be identified, microdosing research may shift away from broad claims about universal cognitive enhancement and toward a more refined, individualised picture of who benefits, on which tasks, and under what circumstances. Until then, the researchers caution, the findings should be treated as preliminary evidence that the answer to whether microdosing works may well be: it depends on who is asking.

Subject of Research: Sex differences in the cognitive effects of LSD microdosing on sustained attention

Article Title: LSD microdosing: Study indicates it makes women’s attention sharper, but no improvement in men

Article References: LSD microdosing: Study indicates it makes women’s attention sharper, but no improvement in men. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: LSD, microdosing, psychedelics, sustained attention, sex differences, cognition, placebo-controlled trial, University of Maastricht, ECNP, attention lapses, neuropsychopharmacology, personalised medicine

The research focused on the left dorsolateral prefrontal cortex, a region tucked into the upper outer portion of the frontal lobes that serves as a hub for cognitive control. This area is heavily involved in planning, working memory, attention regulation, and the flexible redirection of thought when circumstances change. It is also the most common target for repetitive transcranial magnetic stimulation, an approved treatment for treatment-resistant depression. Despite its clinical importance, researchers have lacked objective, neurophysiological markers that connect dysfunction in this region to the specific cognitive impairments seen in patients. The new study set out to fill that gap by asking a deceptively simple question: when you stimulate the left dorsolateral prefrontal cortex and record the brain’s immediate electrical reply, does that reply differ in people with depression, and does it relate to how well they think?

To answer it, the team recruited seventy-nine participants: forty-nine individuals diagnosed with major depressive disorder and thirty healthy controls. Each participant completed a comprehensive clinical assessment along with a battery of executive-function tests spanning multiple cognitive domains, including processing speed, sustained attention, cognitive flexibility, task switching, and the ability to inhibit responses during emotional conflict. The researchers then applied single-pulse transcranial magnetic stimulation over the left dorsolateral prefrontal cortex while simultaneously recording brain activity with electroencephalography, a paired technique known as TMS-EEG. The stimulation was delivered at the F3 scalp position, and the resulting TMS-evoked potentials were measured directly at that electrode, yielding a series of characteristic deflections labeled P30, N45, P60, N100, and P180 according to their polarity and timing in milliseconds after the pulse.

The behavioral results confirmed what prior clinical literature has suggested. Compared with healthy controls, patients with depression performed significantly worse across several domains: they were slower on processing-speed measures, showed reduced sustained attention, struggled more with cognitive flexibility and task switching, and had greater difficulty exerting inhibitory control when faced with emotionally conflicting information. These deficits were not confined to a single test but formed a coherent pattern of multidomain executive dysfunction, reinforcing the view that depression’s cognitive burden is broad rather than narrow, and that it touches the very machinery of self-regulation that people rely on in work, study, and daily decision-making.

The neurophysiological findings were more selective, and that selectivity is what makes them compelling. Of the five TMS-evoked components examined, only one distinguished the groups: the N100, a negative-going deflection appearing roughly one hundred milliseconds after stimulation. Patients with depression showed a significantly larger N100 magnitude at the F3 electrode than healthy controls, while the earlier and later components, P30, N45, P60, and P180, did not differ between the groups. This pattern suggests that the alteration in depression is not a blanket change in cortical responsiveness but a specific modification of the mid-latency inhibitory processing that the N100 is thought to reflect, a component widely associated with GABAergic inhibitory mechanisms in the stimulated cortex.

The most striking result emerged when the researchers looked within the patient group. A more negative N100 amplitude was associated with poorer sustained-attention performance, measured with the Continuous Performance Test, and this correlation survived correction for multiple comparisons using the false discovery rate procedure. In other words, the strength of the brain’s electrical response to direct prefrontal stimulation predicted how well a patient could maintain focus over time. The association was specific enough that the other TEP components did not show the same relationship, hinting that the N100 carries information about a particular cognitive function rather than general brain health.

Skeptics might wonder whether the link simply reflects mood severity, anxiety, or demographic differences rather than a genuine neurocognitive relationship. The research team anticipated this concern and tested it directly with hierarchical multiple linear regression. After statistically adjusting for depressive symptom severity, anxiety symptoms, age, sex, and years of education, the association between N100 amplitude and sustained-attention performance remained significant. This robustness matters because it suggests the N100 is not merely a proxy for how depressed someone feels on the day of testing; it appears to index something about prefrontal cortical function that is tied to attentional capacity in its own right, independent of the clinical and demographic factors that often confound such studies.

The authors also took care to address the possible influence of medication. Supplementary analyses compared patients who were medication-free with those taking antidepressants, and separately with those treated with benzodiazepines, examining both clinical characteristics and TEP amplitudes across these subgroups. Quality metrics for the TMS-EEG preprocessing, resting motor threshold, and stimulation intensity were likewise compared between groups to ensure that the group difference in N100 was not an artifact of differing recording conditions or stimulation parameters. These controls strengthen the case that the observed alteration reflects genuine neurophysiological differences associated with the disorder rather than technical or pharmacological confounds, although the authors are careful to note that the findings require longitudinal validation before the N100 can be considered a clinically useful marker.

Why should this matter beyond the laboratory? First, it provides an objective, physiology-based correlate of cognitive dysfunction in depression, a field that has long relied on subjective reports and behavioral testing alone. A measurable electrical signature recorded in a single session could, with further validation, help clinicians identify which patients carry the greatest cognitive burden, track changes over the course of illness or treatment, and potentially guide neuromodulation therapy by revealing how responsive a patient’s prefrontal cortex is before a treatment course begins. Second, the specificity of the N100-sustained attention link offers a mechanistic clue: it points toward altered inhibitory processing in the left dorsolateral prefrontal cortex as a candidate contributor to the attentional failures that so many patients describe, connecting a cellular-level hypothesis about GABAergic function to a real-world symptom.

The study’s limitations are acknowledged by its authors and deserve emphasis. The design was cross-sectional, meaning it captured a single moment in time and cannot establish whether the altered N100 causes attentional impairment, results from it, or both reflect a shared underlying process. The patient group was heterogeneous in medication status, and while the supplementary analyses addressed this, larger samples will be needed to disentangle drug effects definitively. The authors themselves state that the functional specificity and clinical utility of the F3-recorded N100 require longitudinal validation. Even so, the work represents a meaningful step toward grounding the cognitive symptoms of depression in measurable brain physiology. For the millions of people whose depression is defined as much by foggy thinking and wandering focus as by low mood, the prospect of an objective marker, and eventually a targeted way to monitor and treat cognitive dysfunction, is a development worth watching closely.

Subject of Research: Neurophysiological markers of executive dysfunction in major depressive disorder using TMS-evoked potentials from the left dorsolateral prefrontal cortex

Article Title: Association between executive function and left dorsolateral prefrontal TMS-evoked potentials in major depressive disorder

Article References: Zhang, J.-Q., Zhang, H.-G., An, Q., Cao, M.-N., Deng, W.-Y., Jing, W.-T., Zhao, J.-H., Xue, C., Sun, J.-J., & Deng, W. (2026). Association between executive function and left dorsolateral prefrontal TMS-evoked potentials in major depressive disorder. BMC Psychiatry. https://doi.org/10.1186/s12888-026-08646-1

Image Credits: AI Generated

DOI: 10.1186/s12888-026-08646-1

Keywords: major depressive disorder, executive function, TMS-EEG, TMS-evoked potentials, dorsolateral prefrontal cortex, sustained attention, N100, neurophysiology, cognitive dysfunction, neuromodulation, psychiatry, prefrontal cortex

The research team recruited 23 younger adults and 22 older adults and asked them to perform a demanding dual-task paradigm. The first task was an audiovisual discrimination task, designed to measure how effectively participants combined what they heard with what they saw. The second was a multiple object tracking task, a classic laboratory probe of sustained visual attention in which observers must keep track of several moving targets among identical distractors. By varying the number of objects that participants had to track, the researchers could systematically manipulate sustained attentional load, from a light demand that left plenty of cognitive resources free, through a medium load, to a high load that consumed most of the observer’s attentional capacity. Crucially, the audiovisual stimuli had to be processed simultaneously with the tracking task, so any change in multisensory performance across load levels could be attributed to how attention was being allocated.

The logic of the experiment rests on a long-standing theoretical debate in cognitive neuroscience. According to classic resource theories of attention, dating back to Daniel Kahneman’s influential 1973 work, attention behaves like a finite pool of energy that can be divided among competing tasks. When one task consumes more of the pool, less remains for everything else. Earlier studies had shown that audiovisual speech integration falters when listeners are asked to carry out concurrent demanding tasks, and that attentional load in one modality can alter how signals from other modalities are combined. But most of this evidence came from young participants, and the question of how aging reshapes the load-integration relationship remained open. Older adults experience declines in sensory processing speed, visual acuity, auditory sensitivity, and attentional capacity, all of which could plausibly change the efficiency with which their brains merge cross-modal signals.

The behavioral results revealed a striking divergence between the age groups. Younger adults displayed an inverted U-shaped pattern of audiovisual integration across attentional loads. Their multisensory advantage, the performance benefit gained from presenting sound and vision together rather than separately, peaked when the tracking task imposed a medium load. Under both low-load and high-load conditions, integration was weaker. This pattern suggests that a moderate attentional demand may actually be optimal for binding the senses in young brains, perhaps because light loads leave attention under-engaged while heavy loads drain the resources needed for cross-modal processing. Older adults, by contrast, showed greater audiovisual integration under low and medium loads than under high load, without the same sharp peak at intermediate demand. Their integration profile was flatter and shifted toward the easier conditions, consistent with the idea that their overall pool of attentional resources is smaller and is exhausted earlier as load increases.

Perhaps the most intriguing finding emerged when the researchers examined the time course of integration using electroencephalography. By recording event-related potentials, the tiny voltage fluctuations elicited by stimuli at the scalp, the team could track when in the processing stream multisensory interactions occurred. They identified distinct integration components at different latencies: an early window reflecting relatively automatic sensory-level convergence, an intermediate window, and a late window spanning roughly 420 to 460 milliseconds after stimulus onset. Remarkably, older adults showed enhanced integration during this late window compared with younger adults. Late components of the evoked potential are typically associated with higher-order cognitive operations, including stimulus evaluation, decision formation, and the allocation of working memory. Enhanced late integration in older adults therefore hints at a compensatory strategy in which the aging brain recruits additional, later-stage processing to achieve the multisensory binding that younger brains accomplish earlier and more automatically.

The electrophysiological data also exposed a second age-related difference: timing. The onsets of both the early and intermediate integration components were delayed in older adults relative to their younger counterparts. In other words, even the relatively automatic, sensory-level stages of combining sound and sight began later in the older brain. This delay fits with a broad literature documenting generalized slowing of sensory and neural conduction with age, and it echoes earlier work by the same research group showing that the temporal window within which older adults bind audiovisual stimuli differs from that of young adults. Together, the delayed onsets and the enhanced late activity paint a coherent picture: the aging multisensory system starts later but works longer, extending its integration into time windows that younger brains have already moved past.

These findings carry significant theoretical weight for understanding how the mind changes across the lifespan. One influential framework in cognitive aging neuroscience, the posterior-to-anterior shift in aging, proposes that older adults compensate for reduced efficiency in posterior sensory cortices by recruiting frontal regions typically associated with executive control. The enhanced late audiovisual integration observed here is consistent with such a compensatory account, suggesting that multisensory processing in aging becomes increasingly entangled with higher-order cognitive resources. It also aligns with prior reports that older adults sometimes show stronger multisensory enhancement than young adults in simple detection tasks, a phenomenon that has been interpreted as the aging brain exploiting every available source of information to offset noisier individual senses. When both vision and hearing degrade, combining them yields a proportionally larger benefit, and the present study suggests that this benefit is actively sustained by late-stage neural processing even under attentional pressure.

The study also refines our understanding of the relationship between attention and multisensory integration more generally. Researchers have debated whether binding across the senses requires attention at all, or whether early integration proceeds automatically and only later stages are modulated by attentional focus. The inverted U-shaped load function in young adults supports a nuanced middle position: integration is neither wholly automatic nor wholly dependent on attention, but instead flourishes within an optimal band of attentional engagement. Too little demand may mean the multisensory system is not prioritized; too much demand starves it of resources. The fact that this band shifts with age indicates that the optimal engagement level is not fixed but calibrated to the organism’s total cognitive capacity, a conclusion that resonates with recent work showing that attentional demands in the visual field modulate audiovisual interactions in the temporal domain.

There are, of course, important caveats. The experiments were not preregistered, and the sample sizes, while adequate for detecting the reported effects, are modest. The multiple object tracking task manipulates sustained visual attention specifically, so the findings speak most directly to situations in which vision is the attentionally taxed modality. The authors note that stimulus materials and de-identified data are available from the corresponding author upon reasonable request, and the study received support from the National Natural Science Foundation of China. Future work will need to determine whether the enhanced late integration observed in older adults reflects genuinely compensatory neural recruitment, perhaps in frontal cortex, or a slower and less efficient form of the same computations that younger brains perform earlier.

For everyday life, the implications are tangible. Older adults routinely navigate environments, such as busy streets, crowded restaurants, and conversations in noisy rooms, in which they must divide attention between visual monitoring and auditory-visual communication. If high attentional load degrades multisensory integration more severely in aging, then situations that demand intense visual vigilance may disproportionately impair the ability to combine what older individuals see and hear, with potential consequences for driving safety, social interaction, and fall risk. At the same time, the demonstration that the aging brain can enhance late-stage integration offers an encouraging message: the multisensory system retains plasticity and can adapt its temporal dynamics to meet the demands imposed by a changing cognitive landscape. Understanding and perhaps training these compensatory mechanisms could one day inform interventions designed to preserve effective perception in older age, turning a laboratory curiosity about event-related potentials into a practical tool for healthy aging.

Subject of Research: Age-related changes in how sustained visual attentional load modulates audiovisual integration in younger and older adults

Article Title: Age-related changes in sustained visual attentional modulation of audiovisual integration

Article References: Ren, Y., Xue, H., Yang, M., Wu, Y., Li, Y., & Yang, W. (2026). Age-related changes in sustained visual attentional modulation of audiovisual integration. Attention, Perception, & Psychophysics, 88(7), Article 197. https://doi.org/10.3758/s13414-026-03346-0

Image Credits: AI Generated

DOI: 10.3758/s13414-026-03346-0

Keywords: audiovisual integration, sustained attention, attentional load, aging, event-related potentials, multisensory processing, cognitive aging, multiple object tracking, neural compensation, psychophysics, ERP, older adults