Giorgia Francesca Scaramuzzi

Gamma-band neural activity (>30 Hz) has been linked to associative memory and is increasingly targeted by non-invasive stimulation protocols, although behavioural effects remain variable and may depend on stimulation modality, waveform, montage, and timing. We assessed whether 40 Hz transcranial alternating current stimulation (tACS) or rhythmic auditory stimulation (rAS) modulates face–name associative memory in healthy young adults. One hundred and twenty participants were assigned to one of four stimulation groups: face-network tACS (Fp1–PO8), bitemporal tACS (T7–T8), sine rAS, or square rAS. Each participant completed three conditions during the Italian Face–Name Associative Memory Test: Continuous stimulation across encoding, retention, and retrieval; Intermittent stimulation during encoding and retrieval; and Sham. Primary memory outcomes showed no significant effects of stimulation, with no Condition × Group interactions for Immediate Recall, Delayed Free Recall, or Delayed Total Recall. In the face-network tACS group, Delayed Total Recall was nominally higher after Continuous than Sham stimulation, but this difference did not survive correction for multiple comparisons. Exploratory analyses of recall-error composition showed a significant Condition × Group interaction: in the face-network tACS group, both active conditions differed from Sham, with descriptively fewer interference errors and more intrusion errors. Overall, a single session of 40 Hz tACS or rAS did not reliably enhance face–name associative memory, although face-network tACS may modulate the qualitative pattern of recall errors in a protocol-dependent manner.

Assessing associative memory, particularly in complex paradigms such as face-name association, enables monitoring of cognitive functioning. Electrophysiological correlates of associative memory could provide fundamental insights into the functional role of brain dynamics. This study explored whether resting-state EEG (rsEEG) spectral power and coherence were associated with performance on the Italian Face-Name Association Test (ItFNAT). Thirty-two healthy adults ( M _age = 23.28) underwent an eyes-closed rsEEG recording before the administration of the ItFNAT, which provides scores for immediate recall (IR), delayed free recall (DFR), and delayed total recall (DTR). Frontal, temporal, central and posterior rsEEG spectral power density and theta and gamma network coherence were analyzed in relation to the test scores. High-gamma power (h-γ, 51–100 Hz) was significantly associated with DTR performance, explaining approximately 38% of the adjusted variance. Frontal and temporal h-γ power were positively associated with DTR performance, whereas posterior h-γ power showed a negative association. Furthermore, low-gamma coherence (l-γ, 30–49 Hz) showed trend-wise negative associations with delayed-recall performance. Spontaneous gamma activity showed region-specific associations with face-name memory performance in healthy adults, involving frontal, temporal, and posterior regions. This regional pattern may represent a neurophysiological correlate of individual differences in associative memory retrieval.

Background/Objectives: Unilateral Spatial Neglect (USN) is a disabling attentional syndrome occurring after cortical or subcortical stroke, including thalamic lesions. EEG-based neurofeedback (EEG-NF) may support cortical self-regulation, but evidence in spatial neglect remains limited. This case report describes the clinical, neuropsychological, functional, and electrophysiological (quantitative EEG, qEEG) evolution of a patient with USN after a right thalamic hemorrhagic stroke who underwent multidisciplinary rehabilitation including EEG-NF. Methods: A 70-year-old patient underwent a 3-week inpatient multidisciplinary rehabilitation program including physiotherapy, speech and swallowing therapy, conventional cognitive stimulation, and 15 adjunctive EEG-NF sessions. Baseline and post-treatment assessments included clinical, neuropsychological, neglect-specific, functional, affective, and resting-state qEEG measures. Individual change was examined using the Reliable Change Index when suitable psychometric parameters were available, together with published normative and clinical thresholds. Results: After rehabilitation, the Montreal Cognitive Assessment total raw score increased from 20 to 24, reaching the published minimal clinically important difference but not the minimal detectable change. The Frontal Assessment Battery increased from 8 to 12; after adjustment for age and education according to Italian normative data, both scores remained below the normative cut-off. Neglect-specific measures showed reduced spatial asymmetry, increased contralesional target detection, and a Catherine Bergego Scale reduction from 17 to 5, indicating a shift from moderate to mild ecological neglect. Functional independence improved, with reliable change in Functional Independence Measure (FIM) total and cognitive scores and Modified Barthel Index scores. Exploratory qEEG analyses showed condition-dependent spectral and connectivity changes, but findings were heterogeneous and hypothesis-generating. EEG-NF was completed without adverse events. Conclusions: The adjunctive EEG-NF protocol was completed as planned, with no adverse events. Clinical improvement cannot be attributed specifically to neurofeedback because all rehabilitation components were delivered concurrently. Controlled studies are needed to clarify its specific contribution and the durability of the observed improvements in post-stroke spatial neglect.

Background/Objectives: Unilateral Spatial Neglect (USN) is a disabling attentional syndrome occurring after cortical or subcortical stroke, including thalamic lesions. EEG-based neurofeedback (EEG-NF) may support cortical self-regulation, but evidence in spatial neglect remains limited. This case report describes the clinical, neuropsychological, functional, and electrophysiological (quantitative EEG, qEEG) evolution of a patient with USN after right thalamic hemorrhagic stroke who underwent multidisciplinary rehabilitation including EEG-NF . Methods: A 70-year-old patient underwent a 3-week inpatient multidisciplinary rehabilitation program including physiotherapy, speech and swallowing therapy, conventional cognitive stimulation, and 15 adjunctive EEG-NF sessions. Baseline and post-treatment assessments included clinical, neuropsychological, neglect-specific, functional, affective, and resting-state qEEG measures. Individual change was examined using the Reliable Change Index when suitable psychometric parameters were available, together with published normative and clinical thresholds. Results: After rehabilitation, Montreal Cognitive Assessment total raw score increased from 20 to 24, reaching the published minimal clinically important difference but not the minimal detectable change. The Frontal Assessment Battery increased from 8 to 12, corresponding to a transition from the abnormal to the borderline range according to updated Italian normative data. Neglect-specific measures showed reduced spatial asymmetry, increased contralesional target detection, and a Catherine Bergego Scale reduction from 17 to 5, indicating a shift from moderate to mild ecological neglect. Functional independence improved, with reliable change in Functional Independence Measure (FIM) total and cognitive scores, and Modified Barthel Index scores. Exploratory qEEG analyses showed condition-dependent spectral and connectivity changes, but findings were heterogeneous and hypothesis-generating. EEG-NF was completed without adverse events. Conclusions: The adjunctive EEG-NF protocol was completed as planned, with no adverse events. Clinical improvement cannot be attributed specifically to neurofeedback because all rehabilitation components were delivered concurrently. Controlled studies are needed to clarify its specific contribution and the durability of the observed improvements in post-stroke spatial neglect.

Purpose: Social isolation and loneliness are increasingly recognized as critical psychosocial determinants of cognitive aging and dementia risk. By adopting a multidimensional approach, this study examines how both objective and subjective features of social connectedness relate to cognitive functioning across healthy and older cognitively normal and impaired Italian adults. Methods: In Experiment 1, 662 healthy participants ( M _age= 51.7 years) completed a brief assessment, including measures of general cognition, associative memory and social cognition, subjective cognitive decline and questionnaires on social connectedness. In Experiment 2, 141 older adults ( M _age= 64.29 years) were categorized as cognitively healthy (CH; n=68) and cognitively impaired (CI; n=73) after a comprehensive neuropsychological evaluation. Results: Experiment 1 regression analyses revealed that larger social networks and cohabitation were associated with better associative memory and social cognition, while higher loneliness predicted greater subjective cognitive decline. Notably, the results observed in the larger sample were partially confirmed in experiment 2, with CI group having worse scores in delayed free recall of the Italian Face-Name Association Test. Furthermore, depression, rather than loneliness, was a significant predictor of subjective cognitive complaints, independent of cognitive status. Conclusion: These findings underscore the distinct and interactive roles of objective and subjective social isolation in shaping cognitive trajectories and highlight the importance of integrating psychosocial variables into dementia prevention strategies.

Growing interest in noninvasive neuromodulation posits 40 Hz sensory stimulation as a potential intervention for Alzheimer's disease. Early studies suggested that 40 Hz visual flicker entrains gamma activity and reduces amyloid pathology; however, later work found either absent entrainment or even increased amyloid burden, revealing strong dependence on disease stage, network integrity, and stimulation parameters. Initial clinical investigations suggest that 40 Hz stimulation is safe, well-tolerated, and capable of modulating cortical network dynamics and improving cognition, despite limited effects on amyloid burden. These findings suggest a shift from molecular pathology to network plasticity as the primary target of gamma stimulation.