Our lab investigates human memory and its neural basis using a mixture of behavioral, computational, and neurophysiological strategies. In our computational investigations, we construct mathematical and pc-simulation fashions to account for the dynamics of memory retrieval in a wide range of episodic and spatial Memory Wave duties. Because behavioral knowledge supplies a sparse reflection of the brain’s activity supporting memory, we concurrently report neurophysiological signals as patients with arrays of implanted electrodes perform memory duties. In these investigations we research neural activity at multiple spatial scales, ranging from individual neurons to spatially-distributed networks of subject-potential exercise supporting memory. A number of of our current initiatives also use electrical stimulation to manipulate memory circuits, both for understanding basic memory mechanisms and likewise for growing therapies to revive memory in patients with mind injury or neurological disease. Please click on here for more info and errata. To assist explain the processes underlying encoding, group and retrieval of episodic reminiscences, we have now developed, extended and MemoryWave Official refined a class of fashions primarily based on the idea that items in memory turn into related to a time-varying representation of spatio-temporal context.

The temporal context model (TCM; Howard and Kahana, 2002 and TCM-A Sederberg, Howard, and Kahana, 2008) sought to elucidate the time-scale invariance of recency and contiguity results in free recall, and dissociations between recall of recent and distant memories. Subsequent modeling work generalized TCM past temporal context to account for the influence of semantic information on recall dynamics (CMR, Polyn, Norman, and Kahana (2009)). MATLAB scripts to run the CMR model may be downloaded right here. Lohnas, Polyn, and Memory Wave Kahana (2015) offered a significant overhaul of the sooner CMR model, going beyond earlier modeling of individual lists to clarify the interplay between recollections learned throughout a number of experiences . In their CMR2 mannequin, memory accumulates throughout multiple experimental lists, and temporal context is used both to focus retrieval on a goal listing and to censor retrieved data when its match to the present context signifies that it was discovered in a non-goal listing.

The model concurrently accounts for a variety of intralist and interlist phenomena, including the pattern of prior-checklist intrusions observed in free recall, construct-up of and launch from proactive interference, and the ability to selectively goal retrieval of objects on particular prior lists (Jang & Huber, 2008; Shiffrin, 1970). Healey and Kahana (2015) used CMR2 to higher understand why memory tends to get worse as we age. By fitting CMR2 to the performance of particular person younger and older adults, they identified deficits in 4 important processes: sustaining attention across a study episode, generating retrieval cues, resolving competition, and screening for inaccurate memories (intrusions). Healey and Kahana additionally prolonged CMR2 to simulate a recognition memory process using the identical mechanisms the free recall model uses to reject intrusions. Without fitting any further parameters, the model accounts for age variations in recognition memory accuracy. Confirming a prediction of the mannequin, free recall intrusion rates correlate positively with recognition false alarm rates.

MATLAB scripts to run the CMR2 model can be downloaded right here. Cohen and Kahana (2021, Psychological Assessment) introduced CMR3 to incorporate the essential function of arousal and emotion in human memory. They utilized their model to diverse phenomena including the role of emotion in organizing recollections, state-dependent and mood congruent memory, the position of emotional experiences in producing persistent temper states, including depression, and a novel account of PTSD and its remedy. A evaluate of this line of research appeared in Kahana (2020), Computational Fashions of Memory Search, in the Annual Overview of Psychology. Python code that runs CMR2 and CMR3 could also be downloaded from the lab's publication page. We investigate the neurophysiology of episodic memory with electrocorticographic (ECoG) and single neuron recordings from neurosurgical patients who've had electrodes surgically implanted on the cortical floor of the mind or in the medial temporal lobes (including hippocampus) as part of the clinical technique of localizing seizure foci. One focus of this analysis is to determine the oscillatory correlates of profitable episodic memory formation and retrieval. Analyses of such recordings have proven that prime-frequency activity (HFA, 70-150 Hz) increase whereas participants are studying words that they are going to successfully, versus unsuccessfully, recall.

EEG voltage traces for every item and measure when and the place energy at specific frequencies changes. Profitable memory formation is associated with increases in HFA in left lateral temporal lobe, medial temporal lobe, and left prefrontal cortex. The same analyses will be carried out on gadgets throughout recall to evaluate when and MemoryWave Official where reminiscences are retrieved. Profitable memory retrieval is related to will increase in gamma band activity within the left neocortex and hippocampus as well as increases in theta band (four -eight Hz) exercise in right temporal lobe. The power to reinstate this contextual info throughout memory search has been thought of a hallmark of episodic, or occasion-based, memory. In Manning et al., 2011, we sought to find out whether contextual reinstatement could also be noticed in electrical signals recorded from the human mind throughout episodic recall. We examined ECoG activity from 69 neurosurgical patients as they studied and recalled lists of phrases in a delayed free recall paradigm (Fig. 4A), and computed similarity between the ECoG patterns recorded simply prior to each recall with those recorded after the affected person had studied every phrase.