Memory, crisis and democracy in Africa

This article provides an overview of the Digital Memory Studies Association (dMSA) online roundtable on “Memory, Crisis, Democracy and Africa” which took place on 21 May 2021. It also details how memory can be understood as a democratic phenomenon in postcolonial Africa and examines, at the same time, various crises of memory that emerge in regimes that undermine democracy on the continent. It ends with reflections on the state of memory studies in Africa and suggests various ways of approaching the study of memory and crisis on the continent.

A Remote Digital Memory Composite to Detect Cognitive Impairment in Memory Clinic Samples in Unsupervised Settings using Mobile Devices

INTRODUCTION: Mobile app-based unsupervised monitoring of cognition holds the promise to facilitate case-finding in clinical care and the individual detection of cognitive impairment in clinical and research settings. In the context of Alzheimer's disease, this is particularly relevant for patients who seek medical advice due to memory complaints. OBJECTIVE: We developed a Remote Digital Memory Composite score from an unsupervised remote and mobile cognitive assessment battery focused on episodic memory and long-term recall and assessed its construct validity using a neuropsychological composite score for early cognitive impairment in Alzheimer's disease, the Preclinical Alzheimer's Cognitive Composite (PACC5). We also assessed the test-retest reliability of the Remote Digital Memory Composite score across two independent test sessions. Finally, we assessed the diagnostic accuracy of the remote and unsupervised cognitive assessment battery when predicting PACC5-based cognitive impairment in a memory clinic sample and healthy controls. SETTING: This was an add-on study of the DZNE-Longitudinal Cognitive Impairment and Dementia Study (DELCODE) which was also performed in a separate memory clinic-based sample. PARTICIPANTS A total of 102 study participants were included as healthy controls (HC; n=25), cognitively unimpaired first-degree relatives of AD patients (REL; n=7), individuals with subjective cognitive decline (SCD; n= 48) or patients with mild cognitive impairment (MCI; n=22). MEASUREMENTS: We analyzed results from the objects-in-rooms recall (ORR) test, the mnemonic discrimination for objects and scenes (MDT-OS) test and the complex scene recognition (CSR) test implemented on the neotiv digital platform to derive a Remote Digital Memory Composite. Participants used the neotiv mobile app to complete one unsupervised test session every two weeks on their own mobile device in an environment of their choice. We assessed the relationships of the Remote Digital Memory Composite acquired through the mobile app and in-clinic measures of the PACC5 conducted by trained neuropsychologists in the memory clinics participating in the DELCODE study. RESULTS: 102 participants provided technically complete data for at least one single session of each of the three test paradigms, of which 87 participants provided data from at least two test sessions of each task. The derived Remote Digital Memory Composite score was highly correlated with the PACC5 score across all participants (r=.75, p<0.001), and also in those without complaints (HC and REL, r=.51, p=0.003) and those with complaints separately (SCD and MCI, r=.76, p<0.001). Good test-retest reliability for the Remote Digital Memory Composite score was observed in those with at least two assessments of the three tests. (r=.74; p<.0001). Diagnostic accuracy for discriminating PACC5-based memory impairment from no impairment was high (AUC = 0.9) with a sensitivity of 0.83 and a specificity of 0.74. CONCLUSION: Our results indicate that unsupervised mobile cognitive assessments in a memory clinic setting using the implementation in the neotiv digital platform has high construct validity and results in a good discrimination between cognitively impaired and unimpaired individuals based on the PACC5 score. Thus, it is feasible to complement neuropsychological assessment of episodic memory with unsupervised, remote assessments on mobile devices. This contributes to recent efforts for implementing remotely performed episodic memory assessment for case-finding and monitoring in large research trials and clinical care.

Collective memory or the right to be forgotten? Cultures of digital memory and forgetting in the European Union

This article investigates cultures of digital memory and forgetting in the European Union. The article first gives some background to key debates in media memory studies, before going on to analyse the shaping of European Commission and European Union initiatives in relation to Google’s activities from the period 2004–present. The focus of inquiry for the discussion of memory is the Google Books project and Europeana, a database of digitized cultural collections drawn from European museums, libraries and archives. Attention is then given to questions of forgetting by exploring the tension between Google’s search and indexing mechanisms and the right to be forgotten. The article ends by reflecting on the scale of the shift in contemporary cultures of memory and forgetting, and considers how far European regulation enables possible interventions in this domain.

An Adaptive STDP Learning Rule for Neuromorphic Systems

The promise of neuromorphic computing to develop ultra-low-power intelligent devices lies in its ability to localize information processing and memory storage in synaptic circuits much like the synapses in the brain. Spiking neural networks modeled using high-resolution synapses and armed with local unsupervised learning rules like spike time-dependent plasticity (STDP) have shown promising results in tasks such as pattern detection and image classification. However, designing and implementing a conventional, multibit STDP circuit becomes complex both in terms of the circuitry and the required silicon area. In this work, we introduce a modified and hardware-friendly STDP learning (named adaptive STDP) implemented using just 4-bit synapses. We demonstrate the capability of this learning rule in a pattern recognition task, in which a neuron learns to recognize a specific spike pattern embedded within noisy inhomogeneous Poisson spikes. Our results demonstrate that the performance of the proposed learning rule (94% using just 4-bit synapses) is similar to the conventional STDP learning (96% using 64-bit floating-point precision). The models used in this study are ideal ones for a CMOS neuromorphic circuit with analog soma and synapse circuits and mixed-signal learning circuits. The learning circuit stores the synaptic weight in a 4-bit digital memory that is updated asynchronously. In circuit simulation with Taiwan Semiconductor Manufacturing Company (TSMC) 250 nm CMOS process design kit (PDK), the static power consumption of a single synapse and the energy per spike (to generate a synaptic current of amplitude 15 pA and time constant 3 ms) are less than 2 pW and 200 fJ, respectively. The static power consumption of the learning circuit is less than 135 pW, and the energy to process a pair of pre- and postsynaptic spikes corresponding to a single learning step is less than 235 pJ. A single 4-bit synapse (capable of being configured as excitatory, inhibitory, or shunting inhibitory) along with its learning circuitry and digital memory occupies around 17,250 μm2 of silicon area.

Entropic Associative Memory for Manuscript Symbols

Manuscript symbols can be stored, recognized and retrieved from an entropic digital memory that is associative and distributed but yet declarative; memory retrieval is a constructive operation; symbols not contained in the memory are rejected directly without search; and memory operations can be performed through parallel computations. Manuscript symbols, both letters and numerals, are stored in Associative Memory Registers that have an associated entropy. The memory recognition operation obeys an entropy trade-off between precision and recall, and the entropy level impacts on the quality of the objects recovered through the memory retrieval operation. We discuss the operational characteristics of the system for retrieving objects with both complete and incomplete information, such as severe occlusions. The experiments reported in this paper add evidence that supports the scalability of the framework and its potential for developing practical applications. We also compare the present entropic associative memories to Hopfield’s paradigm and discuss its potential for the study of natural memory.

Dragan Živadinov's Zero-Gravity Theatre

This paper aims to discuss the idea of creating a zero-gravity theatre, pioneered by Dragan Živadinov, a Slovenian conceptual artist. In order to do so, the author turns to Russian philosophical (N. Fyodorov, K. Tsiolkovsky, A Chizhevsky) and artistic sources (K. Malevich), as well as the space exploration envisioned by Slovenian scientist Herman Potocnik Noordung, who influenced Živadinov's cosmokinetic art. Resisting the legacy of cosmists and supremacists, Živadinov designs his objectless antimimetic theatre with a void actor, freed from weight and expected to be replaced by a technical substitute, which emits the actor’s memory from near-equatorial orbit. This article examines the foundations of post-gravity theatre, which are based on three algorithms with the digital memory of the actor: biological (recording of body coordinates), biographical (recording of professional biography), and biomechatronic (recording of genetic structure). These will be controlled by the “umbot” both on stage and in space after the death of the actors. The author focuses on the Biomechanics Noordung production, performed in the stratosphere on board an IL‑76 MDK aircraft. Due to sudden free-fall moments, the performers experienced a state of weightlessness, interpreted as a rehearsal for the future liberation of the body from gravity. In conditions which made it possible to create a dozen modes of weightlessness, the actors could perform in a state of levitation, which was perceived as a unique abstract theatrical performance. Combining Meyerhold’s theory of biomechanics, conceived in the 1920s as a system of exercises for the actor’s body, with Noordung’s research on gravity and ways to overcome it, represented by drawings of a rotating space station, Živadinov realised the idea of theatricalising the cosmos. With this performance, Živadinov shows that an abstract work of art can become truly abstract only if it triumphs over gravity, i. e. if it loses its gravitational orientation (up, down, left, right) and manifests itself in zero gravity.

The new grey of memory: Andrew Hoskins in conversation with Huw Halstead

Andrew Hoskins – interviewed by Huw Halstead – discusses the tensions and paradoxes of memory and place in the connective era. Digital media liberate memory from the spatial archive, but they also create a connective compulsion and dependency, a disconnect from the present moment and a loss of control over memory. The overwhelming abundance and immediacy of digital data breed a placelessness of the digital traces of ourselves, an algorithmic narrowing of information, knowledge and life. The COVID-19 pandemic has intensified this compulsion to record to such an extent that it may be considered a new memory boom, an obsessive desire to remember. Locative and mobile technology may seem to locate us in space more than ever before, but they do so in ways that are beyond our comprehension: our smartphones know more about our locatedness than we do, ushering in a ‘new grey’ in digital memory. Yet, it is critical to be aware of the variegated geography of connective memory – and of Memory Studies itself.