Working Memory

Working Memory

1. Central Executive

   • Several authors[27] have proposed that symptoms of ADHD arise from a primary deficit in a specific executive function (EF) domain such as working memory, response inhibition or a more general weakness in executive control.[28] A meta-analytical review cites several studies that found significant lower group results for ADHD in spatial and verbal working memory tasks, and in several other EF tasks. However, the authors concluded that EF weaknesses neither are necessary nor sufficient to cause all cases of ADHD.[28] Several neurotransmitters, such as dopamine and glutamate may be both involved in ADHD and working memory. Both of these are associated with the frontal brain, self-direction and self-regulation, but cause-effect have not been confirmed so it is unclear whether working memory dysfunction leads to ADHD, ADHD distractibility leads to poor functionality of working memory, or if there is some other connection.[29][30][31]
   • EF/Attention
   • Visuo-Spatial Sketch Pad (inner eye)
   • phonological loop
     • remember phone number
     • Phonological Store (inner ear)
       • speech perception, holds spoken words for 1-2 seconds.
     • Articulatory control process (inner voice)
       • Used to rehearse and store verbal information from inner ear
       • speech production
   • mental arithmetic and problem solving
     • allocates data to the subsystems (in red)
   • Episodic Buffer
     • Long term Memory
   • relates them to long term memory
     • selective attention and inhibition
       • shifts between tasks or retrieval strategies
   • Brain areas
     • Orbitofrontal cortex (OFC)
       • The orbitofrontal cortex (OFC) plays a key role in impulse control, maintenance of set, monitoring ongoing behaviour and socially appropriate behaviours.[5] The orbitofrontal cortex also has roles in representing the value of rewards based on sensory stimuli and evaluating subjective emotional experiences.[8] Lesions can cause disinhibition, impulsivity, aggressive outbursts, sexual promiscuity and antisocial behaviour.[4]
     • anterior cingulate cortex (ACC)
       • The anterior cingulate cortex (ACC) is involved in emotional drives, experience and integration.[5] Associated cognitive functions include inhibition of inappropriate responses, decision making and motivated behaviours. Lesions in this area can lead to low drive states such as apathy, abulia or akinetic mutism and may also result in low drive states for such basic needs as food or drink and possibly decreased interest in social or vocational activities and sex.[5][7]
     • dorsolateral prefrontal cortex (DLPFC)
       • The dorsolateral prefrontal cortex (DLPFC) is involved with "on-line" processing of information such as integrating different dimensions of cognition and behaviour.[5] As such, this area has been found to be associated with verbal and design fluency, ability to maintain and shift set, planning, response inhibition, working memory, organisational skills, reasoning, problem solving and abstract thinking.[4][6]

2. frontal lobes