title: Into the future with little past: exploring mental time travel in a patient with damage to the mammillary bodies/fornix.
abstract: Remembering the past and imaging the future are both manifestations of 'mental time travel'. These processes have been found to be impaired in patients with bilateral hippocampal lesions. Here, we examined the question of whether future thinking is affected by other Papez circuit lesions, namely: damage to the mammillary bodies/fornix.
  
  
  
  Case (SL) was a 43-year-old woman who developed dense anterograde and retrograde amnesia suddenly, as a result of Wernicke-Korsakoff's syndrome. A region of interest volumetric Magnetic resonance imaging (MRI) analysis was performed. We assessed past and future thinking in SL and 11 control subjects of similar age and education with the adapted Autobiographical Interview (AI). Participants also completed a battery of neuropsychological tests.
  
  
  
  Volumetric MRI analyses revealed severely reduced fornix and mammillary body volumes, but intact hippocampi. SL showed substantial, albeit temporally graded retrograde memory deficits on the adapted AI. Strikingly, whilst SL could not provide any specific details of events from the past two weeks or past two years and had impaired recall of events from her late 30s, her descriptions of potential future events were normal in number of event details and plausibility.
  
  
  
  This dissociation of past and future events' performance after mammillary body and fornix damage is at odds with the findings of the majority of patients with adult onset hippocampal amnesia. It suggests that these non-hippocampal regions of the Papez circuit are only critical for past event retrieval and not for the generation of possible future events.
authors.affiliation: a School of Psychology, University of Sydney , Sydney , Australia.
authors.forename: Jacqui
authors.initials: J
authors.lastname: Tedder
authors.affiliation: b ARC Centre of Excellence in Cognition and its Disorders , Sydney , Australia.|c Neuropsychology Unit , Royal Prince Alfred Hospital and Central Clinical School, University of Sydney , Sydney , Australia.
authors.forename: Laurie
authors.initials: L
authors.lastname: Miller
authors.affiliation: b ARC Centre of Excellence in Cognition and its Disorders , Sydney , Australia.|d Neuroscience Research Australia , Sydney , Australia.|e Faculty of Medicine, School of Medical Sciences , University of New South Wales , Sydney , Australia.
authors.forename: Sicong
authors.initials: S
authors.lastname: Tu
authors.affiliation: b ARC Centre of Excellence in Cognition and its Disorders , Sydney , Australia.|d Neuroscience Research Australia , Sydney , Australia.|f Norwich Medical School , University of East Anglia , Norwich , UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Hornberger
authors.affiliation: a School of Psychology, University of Sydney , Sydney , Australia.|b ARC Centre of Excellence in Cognition and its Disorders , Sydney , Australia.
authors.forename: Suncica
authors.initials: S
authors.lastname: Lah
mesh_terms: D000328:Adult; D000425:Alcohol Amnestic Disorder / Q000000981:diagnostic imaging* / Q000523:psychology*; D000647:Amnesia / Q000523:psychology; D000648:Amnesia, Retrograde; D001925:Brain Damage, Chronic / Q000000981:diagnostic imaging* / Q000523:psychology*; D005260:Female; D020712:Fornix, Brain / Q000000981:diagnostic imaging*; D006624:Hippocampus / Q000000981:diagnostic imaging; D006801:Humans; D007092:Imagination; D008279:Magnetic Resonance Imaging; D008326:Mammillary Bodies / Q000000981:diagnostic imaging*; D008568:Memory; D008569:Memory Disorders; D009483:Neuropsychological Tests; D013995:Time
keywords: Thalamus; Wernicke–Korsakoff’s; cognition; diencephalic lesion; memory