Why the other options are wrong:

• show improvement in every general cognitive test.: No boost was found in general cognitive tests, rather than improvement in every test.
• do better than all participants without training.: The trial does not show that trained participants outperformed all untrained people on broader tests.
• fail to improve on the practised tasks.: The participants did improve on the tasks they practised; the missing gain was transfer to more general ability.

Correct Answer: reasoning, planning and problem-solving.

Why this is correct: The first group trained reasoning, planning and problem-solving. Other mental functions belonged to the second group, and obscure online questions were the control task.

Why the other options are wrong:

• only short-term memory and attention.: Short-term memory and attention belonged to the second group, not the first group's full task list.
• answering obscure questions online.: Answering obscure online questions was the third, control group's activity.
• only maths and visuospatial abilities.: Maths and visuospatial abilities belonged to the second group, not the first group's focus.

Correct Answer: general cognitive abilities.

Why this is correct: The researchers report no boost on tests of general cognitive abilities such as memory, reasoning and learning.

Why the other options are wrong:

• physical fitness.: Physical fitness is not the measured category in these memory, reasoning and learning tests.
• emotional mood.: The tests concern cognitive ability, not emotional mood.
• sleep quality.: Sleep quality is not the general cognitive outcome measured in the reported trial.

Correct Answer: lead the study.

Why this is correct: The report identifies Adrian Owen as the neuroscientist who led the study. Peter Snyder gives the later criticism from Brown University.

Why the other options are wrong:

• take part as a volunteer.: Owen is the study leader, not identified as a task-practising volunteer.
• fund the commercial software company.: The report does not identify Owen as the funder of a commercial software company.
• write the critical response from Brown University.: The critical response from Brown University is attributed to Peter Snyder, not Owen.

Correct Answer: fear their memory and mental sharpness are slipping.

Why this is correct: Snyder says commercial programmes mainly target adults well over 60 worried about slipping memory and mental sharpness. The trial participants were instead aged 18 to 60.

Why the other options are wrong:

• have been guaranteed better memory.: The report describes concerns and disputed benefits, not a guarantee of better memory.
• have already recovered all lost memories.: Recovery of all lost memories is not reported; the adults fear decline.
• have no concerns about mental sharpness.: Having no concerns reverses the stated worry about declining memory and mental sharpness.