Table 1.
Summary of memory and simulation performance in relevant patient cases.
| Patient(s) | Relevant paper(s) | Onset/etiology | Neurological damage |
Normal access to general†/personal semantics?†† | Performance on components of episodic simulation†† |
|||
|---|---|---|---|---|---|---|---|---|
| Hippocampal | Extra- hippocampal | Normal access to episodic details? | Normal ability to construct simulations? | Normal ability to encode simulations? | ||||
| KC (NN) | Tulving (1985), Rosenbaum et al. (2005) | Adult/traumatic brain injury | Bilateral | MTL; diencephalon, occipital–temporal lesion; frontal–parietal lesion | Yes/yes – Intact general semantics/some deficit for recent adulthood (AMI–PS) | No – dense retrograde amnesia for past events (AMI–PI, AI–PI) | No – describes future as “blank” when asked about future events | Not tested; anterograde memory deficits reported |
| DB | Klein et al. (2002) | Adult/anoxia following cardiac arrest | Unknown | Unknown | Yes/unknown –intact general semantics/unknown | No – dense retrograde amnesia for past events (LPF; Crovitz) | No – could not imagine personal future events (LPF; although could generate non-personal future, KPF) | Not tested; anterograde memory deficits reported |
| P01 (KN) | Hassabis et al. (2007), McKenna and Gerhand (2002) | Adult/meningoen cephalitis | Bilateral | Abnormalities in bilateral occipital lobes and bilateral amygdala; see also Squire et al. (2011) | Yes/yes – Intact general semantics/intact personal semantics | No – dense retrograde amnesia for past events | Yes – could imagine fictitious scenes with richness and coherence comparable to controls (SC) | Not tested; anterograde memory deficits reported |
| P02 (TT) | Hassabis et al. (2007), Maguire et al. (2006) | Adult/limbic encephalitis (VGKC-Ab) | Bilateral | Some generalized atrophy; see also Squire et al. (2011) | Yes/yes – general semantics intact/some deficit for recent personal semantics (AMI–PS) | No – dense retrograde amnesia for past events (AMI–PI) | Some – could imagine scenarios but significantly reduced richness and coherence relative to controls (SC) | Not tested; anterograde memory deficits reported |
| P03 | Hassabis et al. (2007), Samarasekera et al. (2006) | Adult/limbic encephalitis | Bilateral | Bilateral amygdala only; but see Squire et al. (2011) | Yes/yes – general semantics intact/deficit for childhood personal semantics (AMI–PS) | Some – retrograde amnesia, most dense for childhood, and early adulthood (AMI–PI) | Some – could imagine scenarios but significantly reduced richness and coherence relative to controls (SC) | Not tested; anterograde memory deficits reported |
| P04 (KC3) | Hassabis et al. (2007), Chan et al. (2007) | Adult/limbic encephalitis (VGKC-Ab) | Bilateral | Bilateral amygdala only; but see Squire et al. (2011) | Yes/unknown – intact general semantics/unknown | Some – retrograde memory for past events extended back 10 years | Some – could imagine scenarios but significantly reduced richness and coherence relative to controls (SC) | Not tested; anterograde memory deficits reported |
| P05 | Hassabis et al. (2007) | Adult/limbic encephalitis (VGKC-Ab) | Bilateral | None reported; but see Squire et al. (2011) | Yes/unknown – intact general semantics/unknown | Some – retrograde memory for past events extended back 10 years | Some – could imagine scenarios but significantly reduced richness and coherence relative to controls (SC) | Not tested; anterograde memory deficits reported |
| MC | Andelman et al. (2010) | Adult/anoxia associated with epileptic seizure | Bilateral | None reported | Yes/yes – intact general semantics/personal semantic deficit extends back only 3 years | Some – retrograde amnesia for past events extended back only 3 years (LPF) | No – only vague responses for personal future (LPF; although could generate non-personal future, KPF) | Not tested; anterograde memory deficits reported |
| Jon | Maguire et al. (2001, 2010), Vharga-Khadem et al. (1997) | Birth/perinatal hypoxia | Bilateral | Bilateral putamen, ventral thalamus, and midbrain | Yes/unknown – intact general semantics/unknown | Some – amnesia for past experiences, although preserved recollection of a small number of events | Yes – could imagine fictitious scenes with richness and coherence comparable to controls (SC) | Not tested; anterograde memory deficits reported |
| HC | Vharga-Khadem et al. (1997), Kwan et al. (2010), Rosenbaum et al. (2011), Hurley et al. (2011) | Birth/perinatal hypoxia | Bilateral | Bilateral thalamus and basal ganglia, right retrosplenial cortex | Yes/yes – intact general semantics/intact personal semantics (AI–PE) | Some – amnesia for past experiences; can recall some events but with significantly reduced detail (AI–PI) | No – significantly reduced episodic detail of future simulations (AI–FI, but see Hurley et al., 2011); could imagine fictitious and future scenes (SC) | Not tested; anterograde memory deficits reported |
| GP | Squire et al. (2010), Levy et al. (2004), Bayley et al. (2005) | Adult/limbic encephalitis | Bilateral | Bilateral amygdala, parahippocampal and fusiform gyri, temporal cortex, and left insula | Some/some – mild deficit of general semantics/intact personal semantics on AMI–PS but not AI–PE | Some – preserved memory for past events (AMI–PI), especially remote events (AI–PI) but deficits for recent events (AI–PI) | Some – largely able to imagine future events but reduction in sensory details (AI–FI) | Repetitions: more repetitions of future event details; anterograde memory deficits reported |
| GW | Squire et al. (2010), Bayley et al. (2005), Gold and Squire (2005) | Adult/anoxia after respiratory failure from drug overdose | Bilateral | None reported | Unknown/some – unknown/intact personal semantics on AI–E*, but mild deficit on AMI–PS | Yes – preserved memory for remote and recent past events (AMI–PI, AI–PI*) | Yes* – able to imagine future events with detail comparable to controls (AI–FI) | Repetitions*: more repetitions of future event details; anterograde memory deficits reported |
| JRW | Squire et al. (2010), Gold and Squire (2005) | Adult/ischemia following cardiac arrest | Bilateral | None reported | Unknown/yes – unknown/intact personal semantics (AMI–PS, AI–PE*) | Yes – preserved memory for remote and recent past events (AMI–PI, AI–PI*) | Yes* – able to imagine future events with detail comparable to controls (AI–FI) | Repetitions*: more repetitions of future event details; anterograde memory deficits reported |
| KE | Squire et al. (2010) | Adult/ischemia associated with kidney failure, toxic shock | Bilateral | None reported | Unknown/yes – unknown/intact personal semantics (AI–PE*) | Yes – preserved memory for remote and recent past events (AI–PI*) | Yes* – able to imagine future events with detail comparable to controls (AI–FI) | Repetitions*: more repetitions of future event details; anterograde memory deficits reported |
| LJ | Squire et al. (2010), Gold and Squire (2005) | Adult/no known precipitating event | Bilateral | None reported | Unknown/yes – Unknown/intact personal semantics (AI–PE*) | Yes – preserved memory for remote and recent past events (AI–PI*) | Yes* – able to imagine future events with detail comparable to controls (AI–FI) | Repetitions*: more repetitions of future event details; anterograde memory deficits reported |
| RS | Squire et al. (2010), Bayley et al. (2005), Gold and Squire (2005) | Adult/anoxia after respiratory failure from drug overdose | Bilateral | Small parietal lobes but may be normal variation | Unknown/yes – unknown/intact personal semantics (AMI–PS, AI–PE*) | Yes – preserved memory for remote and recent past events (AMI–PI, AI–PI*) | Yes* – able to imagine future events with detail comparable to controls (AI–FI) | Repetitions*: more repetitions of future event details; anterograde memory deficits reported |
| 21 Children with developmental amnesia | Cooper et al. (2011) | Infancy/neonatal hypoxia/ischemia due to cardiorespiratory disease | Bilateral* | None reported | Yes/unknown– intact general semantics/unknown | Yes* – deficit in recalling past events from testing session the previous day | Yes* – able to imagine scenes with richness and coherence relative to controls (SC) | No* – recall of scenarios imagined the previous day significantly impaired relative to controls |
| P01 | Race et al. (2011) | Adult/limbic encephalitis | Bilateral | Bilateral parahippocampal gyrus | Yes*/yes* – intact on combined measure of general and personal semantics (AI) | Some* – amnesia for remote and recent past events; some events recalled but with less detail than to controls (AI–PI) | Some* – able to imagine some future events, though with reduced detail relative to controls (AI–FI) | Repetitions*: very few repetitions evident |
| P02 | Race et al. (2011) | Adult/limbic encephalitis | Bilateral | Right lateral temporal cortex, bilateral parahippocampal gyrus | Yes*/yes* – intact on combined measure of general and personal semantics (AI) | Some* – amnesia for remote and recent past events; some events recalled but with less detail than to controls (AI–PI) | Some* – able to imagine some future events, though with reduced detail relative to controls (AI–FI) | Repetitions*: very few repetitions evident |
| P03 | Race et al. (2011) | Adult/anoxia | Unknown | Unknown | Yes*/yes* – intact on combined measure of general and personal semantics (AI) | Some* – amnesia for remote and recent past events; some events recalled but with less detail than to controls (AI–PI) | Some* – able to imagine some future events, though with reduced detail relative to controls (AI–FI) | Repetitions*: very few repetitions evident |
| P04 | Race et al. (2011) | Adult/anoxia | Bilateral | Left lateral temporal cortex, bilateral parahippocampal gyrus | Yes*/yes* – intact on combined measure of general and personal semantics (AI) | Some* – amnesia for remote and recent past events; some events recalled but with less detail than to controls (AI–PI) | Some* – able to imagine some future events, though with reduced detail relative to controls (AI–FI) | Repetitions*: very few repetitions evident |
| P06 | Race et al. (2011) | Adult/limbic encephalitis | Unknown | Unknown | Yes*/yes* – intact on combined measure of general and personal semantics (AI) | Some* – amnesia for remote and recent past events; some events recalled but with less detail than to controls (AI–PI) | Some* – able to imagine some future events, though with reduced detail relative to controls (AI–FI) | Repetitions*: very few repetitions evident |
| P07 | Race et al. (2011) | Adult/anoxia | Unknown | Unknown | Yes*/yes* – intact on combined measure of general and personal semantics (AI) | Some* – amnesia for remote and recent past events; some events recalled but with less detail than to controls (AI–PI) | Some* – able to imagine some future events, though with reduced detail relative to controls (AI–FI) | Repetitions*: very few repetitions evident |
| P08 | Race et al. (2011) | Adult/anoxia | Unknown | Unknown | Yes*/yes* – intact on combined measure of general and personal semantics (AI) | Some* – amnesia for remote and recent past events; some events recalled but with less detail than to controls (AI–PI) | Some* – able to imagine some future events, though with reduced detail relative to controls (AI–FI) | Repetitions*: very few repetitions evident |
| P05 | Race et al. (2011) | Adult/anoxia | Right | None reported | Yes/yes – intact on combined measure of general and personal semantics (AI) | Some – amnesia for remote and recent past events; recalls some events but with reduced detail relative to controls (AI–PI) | Some – able to imagine some future events, though with reduced detail relative to controls (AI–FI) | Repetitions*: very few repetitions evident |
VGKC-Ab, antibodies to voltage-gated potassium channels.
*Only mean performance of patient group reported.
†Retrograde memory for general semantic knowledge tested with measures including: WAIS Information, Comprehension and Vocabulary subtests, famous faces, public events, category judgments, speeded sentence verification.
††Tests noted where reported. AMI, autobiographical memory interview (Kopelman et al., 1989); AI–PI, autobiographical interview – past internal detail score (Levine et al., 2002); AI–PE, autobiographical interview – past external detail score (Levine et al., 2002); AI–FI, autobiographical interview – future internal detail score (Addis et al., 2008); Crovitz, Crovitz cueing task (Crovitz and Schiffman, 1974). LPF, lived past-future (Klein et al., 2002); KPF, known past-future (Klein et al., 2002); SC, scene construction paradigm (Hassabis et al., 2007).